diff --git a/CMakeLists.txt b/CMakeLists.txt
index 32b424a..d340689 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -121,7 +121,12 @@ set(SOURCES
         src/game/physics/holes/layouts/hole_layout.cpp
         src/game/physics/holes/layouts/hole_layout.hpp
         src/game/physics/holes/layouts/depth_hole_layout.hpp
-        src/game/physics/holes/layouts/depth_hole_description.hpp src/game/physics/holes/collectable_sim_ground_segment.hpp src/game/physics/holes/collectable_sim_ground_segment.cpp)
+        src/game/physics/holes/layouts/depth_hole_description.hpp
+        src/game/physics/holes/ground/collectable_sim_ground_segment.hpp
+        src/game/physics/holes/ground/collectable_sim_ground.cpp
+        src/game/physics/holes/ground/collectable_sim_ground.hpp
+        src/game/physics/body_adapter.cpp
+        src/game/physics/body_adapter.hpp)
 
 set(PHYSICS_00_SOURCES
         src/prototypes/physics_00.cpp)
diff --git a/src/config.h b/src/config.h
index ed180d7..8200033 100644
--- a/src/config.h
+++ b/src/config.h
@@ -11,6 +11,7 @@
 #define DEFAULT_PLAYER_POINTS 0
 #define PLAYER_MIN_RADIUS 0.5f    // World units
 #define PLAYER_RADIUS_PER_LEVEL 0.25f
+#define DEFAULT_MAX_PLAYER_NUMBER 4
 
 // World
 #define WORLD_GRAVITY b2Vec2(0.f, -9.8f)
diff --git a/src/game/physics/body_adapter.cpp b/src/game/physics/body_adapter.cpp
new file mode 100644
index 0000000..30bd17c
--- /dev/null
+++ b/src/game/physics/body_adapter.cpp
@@ -0,0 +1,82 @@
+#include "body_adapter.hpp"
+
+#include "../../config.h"
+
+BodyAdapter::BodyAdapter(std::shared_ptr<b2World> world)
+        : world(std::move(world)), bodyObject(nullptr)
+{}
+
+BodyAdapter::~BodyAdapter()
+{
+    destroyBody();
+}
+
+void BodyAdapter::destroyBody()
+{
+    if (bodyObject != nullptr)
+    {
+        world->DestroyBody(bodyObject);
+    }
+}
+
+
+void BodyAdapter::createSquare(b2BodyType type, sf::Vector2f center, sf::Vector2f size)
+{
+    destroyBody();
+
+    b2BodyDef bodyDef;
+    bodyDef.type = type;
+    bodyDef.angularDamping = COLLECTABLES_SIM_ANGULAR_DAMPING;
+    bodyDef.linearDamping = COLLECTABLES_SIM_LINEAR_DAMPING;
+    bodyDef.position.Set(center.x, center.y);
+    bodyObject = world->CreateBody(&bodyDef);
+
+    setBoxSize(size);
+}
+
+b2Body *BodyAdapter::body() const
+{
+    return bodyObject;
+}
+
+sf::Vector2f BodyAdapter::getCenter() const
+{
+    auto position = bodyObject->GetPosition();
+    auto velocity = bodyObject->GetLinearVelocity();
+    return sf::Vector2f(position.x, position.y) + sf::Vector2f(velocity.x, velocity.y);
+}
+
+sf::Vector2f BodyAdapter::getSize() const
+{
+    return boundingBox;
+}
+
+void BodyAdapter::setCenter(sf::Vector2f center)
+{
+    // Set via velocity
+    auto velocity = bodyObject->GetLinearVelocity();
+    velocity += b2Vec2(center.x, center.y) - bodyObject->GetPosition();
+    bodyObject->SetLinearVelocity(velocity);
+}
+
+void BodyAdapter::setBoxSize(sf::Vector2f size)
+{
+    // Remove old fixture
+    if (bodyObject->GetFixtureList() != nullptr)
+    {
+        bodyObject->DestroyFixture(bodyObject->GetFixtureList());
+    }
+
+    // Recreates a square fixture
+    b2PolygonShape shape;
+    shape.SetAsBox(size.x / 2.f, size.y / 2.f);
+    boundingBox = size;
+
+    b2FixtureDef fixtureDef;
+    fixtureDef.shape = &shape;
+    fixtureDef.friction = COLLECTABLES_SIM_FRICTION;
+    fixtureDef.restitution = COLLECTABLES_SIM_RESTITUTION;
+    fixtureDef.density = COLLECTABLES_SIM_DENSITY;
+
+    bodyObject->CreateFixture(&fixtureDef);
+}
diff --git a/src/game/physics/body_adapter.hpp b/src/game/physics/body_adapter.hpp
new file mode 100644
index 0000000..1597d43
--- /dev/null
+++ b/src/game/physics/body_adapter.hpp
@@ -0,0 +1,37 @@
+#ifndef HOLESOME_BODY_ADAPTER_HPP
+#define HOLESOME_BODY_ADAPTER_HPP
+
+
+#include <box2d/box2d.h>
+#include <memory>
+#include <SFML/System/Vector2.hpp>
+
+class BodyAdapter
+{
+public:
+    explicit BodyAdapter(std::shared_ptr<b2World> world);
+    ~BodyAdapter();
+
+    [[nodiscard]] b2Body *body() const;
+
+    void createSquare(b2BodyType type, sf::Vector2f center, sf::Vector2f size);
+
+    [[nodiscard]] sf::Vector2f getCenter() const;
+
+    void setCenter(sf::Vector2f center);
+
+    [[nodiscard]] sf::Vector2f getSize() const;
+
+    void setBoxSize(sf::Vector2f size);
+
+private:
+    std::shared_ptr<b2World> world;
+    b2Body *bodyObject;
+
+    sf::Vector2f boundingBox;
+
+    void destroyBody();
+};
+
+
+#endif //HOLESOME_BODY_ADAPTER_HPP
diff --git a/src/game/physics/holes/collectable_sim_ground_segment.cpp b/src/game/physics/holes/collectable_sim_ground_segment.cpp
deleted file mode 100644
index 91fbc67..0000000
--- a/src/game/physics/holes/collectable_sim_ground_segment.cpp
+++ /dev/null
@@ -1 +0,0 @@
-#include "collectable_sim_ground_segment.hpp"
\ No newline at end of file
diff --git a/src/game/physics/holes/collectable_sim_ground_segment.hpp b/src/game/physics/holes/collectable_sim_ground_segment.hpp
deleted file mode 100644
index 39d5347..0000000
--- a/src/game/physics/holes/collectable_sim_ground_segment.hpp
+++ /dev/null
@@ -1,14 +0,0 @@
-#ifndef HOLESOME_COLLECTABLE_SIM_GROUND_SEGMENT_HPP
-#define HOLESOME_COLLECTABLE_SIM_GROUND_SEGMENT_HPP
-
-#include <box2d/box2d.h>
-
-class CollectableSimGroundSegment
-{
-public:
-    int leftHoleId;
-    int rightHoleId;
-    b2Body *body;
-};
-
-#endif //HOLESOME_COLLECTABLE_SIM_GROUND_SEGMENT_HPP
diff --git a/src/game/physics/holes/collectable_simulation.cpp b/src/game/physics/holes/collectable_simulation.cpp
index 127d565..dc91abd 100644
--- a/src/game/physics/holes/collectable_simulation.cpp
+++ b/src/game/physics/holes/collectable_simulation.cpp
@@ -11,9 +11,14 @@ CollectableSimulation::CollectableSimulation(const std::shared_ptr<Collectable>
     world = std::make_shared<b2World>(WORLD_GRAVITY);
     world->SetAllowSleeping(COLLECTABLES_SIM_SLEEPING);
 
+    // Create ground
+    simGround = std::make_shared<CollectableSimGround>(world);
+//    Todo: Set proper ground width
+
     // Create body
+    collectableBody = std::make_shared<BodyAdapter>(world);
     auto coordinates = collectable->coordinates->diagonalWorld();
-    body = addSquareBody(b2_dynamicBody, {coordinates.horizontal, coordinates.vertical}, sf::Vector2f(1, 1));
+    collectableBody->createSquare(b2_dynamicBody, {coordinates.horizontal, coordinates.vertical}, sf::Vector2f(1, 1));
 }
 
 void CollectableSimulation::physicsUpdate()
@@ -25,28 +30,6 @@ void CollectableSimulation::physicsUpdate()
     updateCollectable();
 }
 
-b2Body *CollectableSimulation::addSquareBody(b2BodyType type, sf::Vector2f center, sf::Vector2f size)
-{
-    b2BodyDef bodyDef;
-    bodyDef.type = type;
-    bodyDef.angularDamping = COLLECTABLES_SIM_ANGULAR_DAMPING;
-    bodyDef.linearDamping = COLLECTABLES_SIM_LINEAR_DAMPING;
-    bodyDef.position.Set(center.x, center.y);
-    b2Body *body = world->CreateBody(&bodyDef);
-
-    b2PolygonShape shape;
-    shape.SetAsBox(size.x / 2.f, size.y / 2.f);
-
-    b2FixtureDef fixtureDef;
-    fixtureDef.shape = &shape;
-    fixtureDef.friction = COLLECTABLES_SIM_FRICTION;
-    fixtureDef.restitution = COLLECTABLES_SIM_RESTITUTION;
-    fixtureDef.density = COLLECTABLES_SIM_DENSITY;
-
-    body->CreateFixture(&fixtureDef);
-    return body;
-}
-
 std::shared_ptr<Collectable> CollectableSimulation::getCollectable() const
 {
     return collectable;
@@ -56,15 +39,25 @@ void CollectableSimulation::updateGroundHole()
 {
     auto holeLayout = HoleLayout::getInstance()->atDepth(collectable->getDepth());
 
+    if (holeLayout.holes.empty())
+    {
+        simGround->closeAllHoles();
+        return;
+    }
 
+    // TODO: Remove assumption
+    // Assume only one hole
+    auto hole = holeLayout.holes[0];
+
+//    todo: Update ground hole
 }
 
 void CollectableSimulation::updateCollectable()
 {
-    auto bodyPosition = body->GetPosition();
+    auto bodyPosition = collectableBody->body()->GetPosition();
     collectable->coordinates->setDiagonal({bodyPosition.x, bodyPosition.y, collectable->getDepth()});
 
     // Convert radians to degrees
-    float angle = body->GetAngle() * 180 / M_PI;
+    float angle = collectableBody->body()->GetAngle() * 180 / M_PI;
     collectable->setRotation(angle);
 }
diff --git a/src/game/physics/holes/collectable_simulation.hpp b/src/game/physics/holes/collectable_simulation.hpp
index a24e5d2..8ce1cdf 100644
--- a/src/game/physics/holes/collectable_simulation.hpp
+++ b/src/game/physics/holes/collectable_simulation.hpp
@@ -3,8 +3,12 @@
 
 
 #include <box2d/box2d.h>
+#include <map>
 #include "../../game_object.h"
 #include "../../collectables/collectable.hpp"
+#include "ground/collectable_sim_ground_segment.hpp"
+#include "ground/collectable_sim_ground.hpp"
+#include "../body_adapter.hpp"
 
 class CollectableSimulation : public GameObject
 {
@@ -17,15 +21,15 @@ public:
 
 private:
     std::shared_ptr<b2World> world;
-    b2Body* body;
+    std::shared_ptr<BodyAdapter> collectableBody;
     
     std::shared_ptr<Collectable> collectable;
 
+    std::shared_ptr<CollectableSimGround> simGround;
+
     void updateGroundHole();
 
     void updateCollectable();
-
-    b2Body *addSquareBody(b2BodyType type, sf::Vector2f center, sf::Vector2f size);
 };
 
 
diff --git a/src/game/physics/holes/ground/collectable_sim_ground.cpp b/src/game/physics/holes/ground/collectable_sim_ground.cpp
new file mode 100644
index 0000000..09f72dc
--- /dev/null
+++ b/src/game/physics/holes/ground/collectable_sim_ground.cpp
@@ -0,0 +1,102 @@
+#include "collectable_sim_ground.hpp"
+
+#include <utility>
+#include "../../../../config.h"
+
+void CollectableSimGround::closeAllHoles()
+{
+    segments.clear();
+
+    // Create one segment for the ground
+    auto groundSegment = std::make_shared<CollectableSimGroundSegment>(world);
+    groundSegment->body->createSquare(b2_kinematicBody,
+                                      {0, -COLLECTABLES_SIM_GROUND_THICKNESS / 2.f},
+                                      {groundWidth, COLLECTABLES_SIM_GROUND_THICKNESS});
+
+    segments.push_back(groundSegment);
+}
+
+CollectableSimGround::CollectableSimGround(std::shared_ptr<b2World> world, float groundWidth)
+        : world(std::move(world))
+{
+    setGroundWidth(groundWidth);
+    closeAllHoles();
+}
+
+void CollectableSimGround::setGroundWidth(float width)
+{
+    if (width <= 0)
+    {
+        throw std::runtime_error("Ground width must be greater than 0");
+    }
+
+    if (width == groundWidth)
+    {
+        return;
+    }
+
+    groundWidth = width;
+    updateOuterSegmentsToWidth();
+}
+
+void CollectableSimGround::updateOuterSegmentsToWidth()
+{
+    auto outerSegments = getOuterSegments();
+    auto borderPoints = groundWidth / 2.f;
+
+    // Left segment
+    if (outerSegments.left != nullptr)
+    {
+        auto leftSegment = outerSegments.left->body;
+        auto leftCenter = leftSegment->getCenter();
+        auto leftSize = leftSegment->getSize();
+        auto deltaToBorder = borderPoints - abs(leftCenter.x - leftSize.x / 2.f);
+
+        // Increase width if positive, decrease if negative
+        leftSize.x += deltaToBorder;
+        leftCenter.x -= deltaToBorder / 2.f;
+
+        leftSegment->setBoxSize(leftSize);
+        leftSegment->setCenter(leftCenter);
+    }
+
+    // Right segment
+    if (outerSegments.right != nullptr)
+    {
+        auto rightSegment = outerSegments.right->body;
+        auto rightCenter = rightSegment->getCenter();
+        auto rightSize = rightSegment->getSize();
+        auto deltaToBorder = borderPoints - abs(rightCenter.x + rightSize.x / 2.f);
+
+        // Increase width if positive, decrease if negative
+        rightSize.x += deltaToBorder;
+        rightCenter.x += deltaToBorder / 2.f;
+
+        rightSegment->setBoxSize(rightSize);
+        rightSegment->setCenter(rightCenter);
+    }
+}
+
+CollectableSimGround::SideSegments CollectableSimGround::getOuterSegments(int holeId)
+{
+    SideSegments sideSegments;
+
+    for (const auto &segment: segments)
+    {
+        // If valid holeId, match left hole id
+        // If invalid holeId, get outer segment
+        if ((segment->leftHoleId == holeId && holeId >= 0)
+            || (segment->rightHoleId < 0 && holeId < 0))
+        {
+            sideSegments.right = segment;
+        }
+
+        if ((segment->rightHoleId == holeId && holeId >= 0)
+            || (segment->leftHoleId < 0 && holeId < 0))
+        {
+            sideSegments.left = segment;
+        }
+    }
+
+    return sideSegments;
+}
diff --git a/src/game/physics/holes/ground/collectable_sim_ground.hpp b/src/game/physics/holes/ground/collectable_sim_ground.hpp
new file mode 100644
index 0000000..3306082
--- /dev/null
+++ b/src/game/physics/holes/ground/collectable_sim_ground.hpp
@@ -0,0 +1,34 @@
+#ifndef HOLESOME_COLLECTABLE_SIM_GROUND_HPP
+#define HOLESOME_COLLECTABLE_SIM_GROUND_HPP
+
+
+#include <vector>
+#include <memory>
+#include "collectable_sim_ground_segment.hpp"
+
+class CollectableSimGround
+{
+public:
+    CollectableSimGround(std::shared_ptr<b2World> world, float groundWidth = 1000);
+
+    void closeAllHoles();
+
+    void setGroundWidth(float width);
+
+private:
+    std::vector<std::shared_ptr<CollectableSimGroundSegment>> segments;
+    std::shared_ptr<b2World> world;
+    float groundWidth;
+
+    struct SideSegments {
+        std::shared_ptr<CollectableSimGroundSegment> left;
+        std::shared_ptr<CollectableSimGroundSegment> right;
+    };
+
+    SideSegments getOuterSegments(int holeId = -1);
+
+    void updateOuterSegmentsToWidth();
+};
+
+
+#endif //HOLESOME_COLLECTABLE_SIM_GROUND_HPP
diff --git a/src/game/physics/holes/ground/collectable_sim_ground_segment.hpp b/src/game/physics/holes/ground/collectable_sim_ground_segment.hpp
new file mode 100644
index 0000000..28632f2
--- /dev/null
+++ b/src/game/physics/holes/ground/collectable_sim_ground_segment.hpp
@@ -0,0 +1,22 @@
+#ifndef HOLESOME_COLLECTABLE_SIM_GROUND_SEGMENT_HPP
+#define HOLESOME_COLLECTABLE_SIM_GROUND_SEGMENT_HPP
+
+#include <box2d/box2d.h>
+#include <memory>
+#include "../layouts/depth_hole_description.hpp"
+#include "../../body_adapter.hpp"
+
+class CollectableSimGroundSegment
+{
+public:
+    explicit CollectableSimGroundSegment(const std::shared_ptr<b2World>& world)
+    {
+        body = std::make_shared<BodyAdapter>(world);
+    }
+
+    int leftHoleId = -1;
+    int rightHoleId = -1;
+    std::shared_ptr<BodyAdapter> body;
+};
+
+#endif //HOLESOME_COLLECTABLE_SIM_GROUND_SEGMENT_HPP
diff --git a/src/game/physics/holes/layouts/depth_hole_layout.hpp b/src/game/physics/holes/layouts/depth_hole_layout.hpp
index f57c793..8fbea95 100644
--- a/src/game/physics/holes/layouts/depth_hole_layout.hpp
+++ b/src/game/physics/holes/layouts/depth_hole_layout.hpp
@@ -3,6 +3,7 @@
 
 #include <vector>
 #include "depth_hole_description.hpp"
+#include "../../../../logging/easylogging++.h"
 
 struct DepthHoleLayout
 {
@@ -12,6 +13,26 @@ struct DepthHoleLayout
     DepthHoleLayout(float depth, std::vector<DepthHoleDescription> holes)
             : depth(depth), holes(std::move(holes))
     {}
+
+    [[nodiscard]] DepthHoleDescription getHole(int playerId) const
+    {
+        for (const auto &hole: holes)
+        {
+            if (hole.playerId == playerId)
+            {
+                return hole;
+            }
+        }
+
+        throw std::runtime_error(
+                "No hole for player " + std::to_string(playerId) + " at depth " + std::to_string(depth) +
+                " in layout.");
+    }
+
+    [[nodiscard]] bool hasHole(int playerId) const
+    {
+        return std::ranges::any_of(holes, [playerId](const auto &hole) { return hole.playerId == playerId; });
+    }
 };
 
 #endif //HOLESOME_DEPTH_HOLE_LAYOUT_HPP
diff --git a/src/game/player/player_collection.cpp b/src/game/player/player_collection.cpp
index 7018075..00aa517 100644
--- a/src/game/player/player_collection.cpp
+++ b/src/game/player/player_collection.cpp
@@ -4,7 +4,8 @@
 #include "../input/input_mapper.h"
 #include "../../texture_config.h"
 
-PlayerCollection::PlayerCollection()
+PlayerCollection::PlayerCollection(int maxPlayerCount)
+        : maxPlayerCount(maxPlayerCount)
 {
     // Set default spawn point
     setSpawnPoints({{0, 0}});
@@ -29,6 +30,7 @@ void PlayerCollection::addPlayer(const std::shared_ptr<Player> &player)
 {
     newPlayerBuffer.push_back(player);
     addDetachedChild(player);
+    updateInputIdentityAllowance();
 }
 
 void PlayerCollection::clear()
@@ -47,6 +49,7 @@ void PlayerCollection::clear()
     }
 
     clearChildren();
+    updateInputIdentityAllowance();
 }
 
 void PlayerCollection::lateUpdate()
@@ -77,6 +80,7 @@ void PlayerCollection::removePlayer(const std::shared_ptr<Player> &player)
 {
     removedPlayerBuffer.push_back(player);
     removeChild(player);
+    updateInputIdentityAllowance();
 }
 
 std::vector<std::shared_ptr<Player>> PlayerCollection::getNewPlayers() const
@@ -130,3 +134,13 @@ std::shared_ptr<Player> PlayerCollection::getPlayerById(int playerId) const
     }
     throw std::runtime_error("Player with id " + std::to_string(playerId) + " not found");
 }
+
+int PlayerCollection::getMaxPlayerCount() const
+{
+    return maxPlayerCount;
+}
+
+void PlayerCollection::updateInputIdentityAllowance() const
+{
+    InputMapper::getInstance()->allowNewInputIdentities = getPlayers().size() < maxPlayerCount;
+}
diff --git a/src/game/player/player_collection.hpp b/src/game/player/player_collection.hpp
index c3d5bfb..ac3aaaf 100644
--- a/src/game/player/player_collection.hpp
+++ b/src/game/player/player_collection.hpp
@@ -8,7 +8,7 @@
 class PlayerCollection : public GameObject
 {
 public:
-    PlayerCollection();
+    explicit PlayerCollection(int maxPlayerCount = DEFAULT_MAX_PLAYER_NUMBER);
 
     static std::shared_ptr<PlayerCollection> getInstance();
 
@@ -26,6 +26,8 @@ public:
 
     [[nodiscard]] std::vector<std::shared_ptr<Player>> getRemovedPlayers() const;
 
+    [[nodiscard]] int getMaxPlayerCount() const;
+
     void lateUpdate() override;
 
     void clear();
@@ -40,6 +42,10 @@ private:
     int nextSpawnPointIndex = 0;
 
     void spawnPlayer(const std::shared_ptr<InputIdentity> &inputIdentity);
+
+    int maxPlayerCount;
+
+    void updateInputIdentityAllowance() const;
 };
 
 
diff --git a/src/levels.hpp b/src/levels.hpp
index b155794..344c8d2 100644
--- a/src/levels.hpp
+++ b/src/levels.hpp
@@ -12,7 +12,7 @@ std::map<std::string, LevelConfig> const all_levels = {
                                             {18, 18},
                                             {0,  18},
                                             {18, 0}}, {
-                                        CollectableInLevel("box", {0, 0})
+                                        CollectableInLevel("box", {3, 5})
                                 },
                                 {
                                         // Blues