diff --git a/.vscode/c_cpp_properties.json b/.vscode/c_cpp_properties.json
index f29000d..9c63d3e 100644
--- a/.vscode/c_cpp_properties.json
+++ b/.vscode/c_cpp_properties.json
@@ -11,7 +11,8 @@
                 "dependencies/include/SDL2",
                 "dependencies/imgui",
                 "${default}"
-            ]
+            ],
+            "cppStandard": "c++20"
         }
     ],
     "version": 4
diff --git a/dependencies/src-csharp.config b/dependencies/src-csharp.config
new file mode 100755
index 0000000..f679ca8
--- /dev/null
+++ b/dependencies/src-csharp.config
@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+DEP_WORKING_DIR='src-csharp'
+if [[ "$TASK" = *_dbg ]]; then
+    DEP_BUILD_COMMAND='dotnet build src-csharp.sln -o bin -c Debug'
+else
+    DEP_BUILD_COMMAND='dotnet build src-csharp.sln -o bin -c Release'
+fi
+DEP_CLEAN_COMMAND='rm -rf bin obj'
+DEP_OTHER_OUT_FILES='bin/Ougge.dll'
diff --git a/project.config b/project.config
index 407c39b..95b7b07 100755
--- a/project.config
+++ b/project.config
@@ -6,7 +6,7 @@ PROJECT="ougge"
 CMP_C="gcc"
 CMP_CPP="g++"
 STD_C="c11"
-STD_CPP="c++17"
+STD_CPP="c++20"
 WARN_C="-Wall -Wno-discarded-qualifiers -Wextra -Wno-unused-parameter"
 WARN_CPP="-Wall -Wextra -Wno-unused-parameter"
 SRC_C="$(find src -name '*.c')"
@@ -16,7 +16,7 @@ SRC_CPP="$(find src -name '*.cpp')"
 # See cbuild/example_dependency_configs
 DEPENDENCY_CONFIGS_DIR='dependencies'
 # List of dependency config files in DEPENDENCY_CONFIGS_DIR separated by space.
-ENABLED_DEPENDENCIES='precompiled resources imgui'
+ENABLED_DEPENDENCIES='precompiled resources imgui src-csharp'
 
 # OBJDIR structure:
 #  ├── objects/      - Compiled object files. Cleans on each call of build task
diff --git a/src-csharp/GameObject.cs b/src-csharp/GameObject.cs
new file mode 100644
index 0000000..235cb4b
--- /dev/null
+++ b/src-csharp/GameObject.cs
@@ -0,0 +1,24 @@
+using System.Management.Instrumentation;
+using System.Numerics;
+using System.Runtime.InteropServices;
+
+namespace Ougge;
+
+[StructLayout(LayoutKind.Sequential)]
+public struct Transform
+{
+    Vector2 scale;
+    Vector2 position;
+    float rotation;
+}
+
+public class Component
+{
+    GameObject owner;
+}
+
+public class GameObject
+{
+    Transform transform { get; }
+    GameObject? parent;
+}
\ No newline at end of file
diff --git a/src-csharp/Script.cs b/src-csharp/Script.cs
index 69801e4..0713b16 100644
--- a/src-csharp/Script.cs
+++ b/src-csharp/Script.cs
@@ -1,5 +1,4 @@
 using System;
-using System.Data;
 
 namespace Ougge;
 
diff --git a/src/Game/GameObject.cpp b/src/Game/GameObject.cpp
new file mode 100644
index 0000000..42ab42b
--- /dev/null
+++ b/src/Game/GameObject.cpp
@@ -0,0 +1,29 @@
+#include "GameObject.hpp"
+
+std::ostream& operator<<(std::ostream& s, Transform& t){
+    s<<"{ position: {x: "<<t.position.x<<", y: "<<t.position.y;
+    s<<"}, rotation: "<<t.rotation;
+    s<<", scale {x: "<<t.scale.x<<", y: "<<t.scale.y<<"} }";
+    return s;
+}
+
+GameObject::GameObject(Mono::Object managed_obj, GameObject *parent)
+    : object_handle(managed_obj), parent(parent) 
+{}
+
+GameObject &GameObject::operator=(GameObject &&o){ 
+    transform = o.transform;
+    components = std::move(o.components);
+    object_handle = std::move(o.object_handle);
+    return *this;
+}
+
+bool GameObject::tryGetComponent(const std::u16string &name, Component **out_component)
+{
+    return false;
+}
+
+bool GameObject::tryAddComponent(const std::u16string &name, Component &&component)
+{
+    return false;
+}
diff --git a/src/Game/GameObject.hpp b/src/Game/GameObject.hpp
index fa2c281..cbf8ec3 100644
--- a/src/Game/GameObject.hpp
+++ b/src/Game/GameObject.hpp
@@ -1,15 +1,41 @@
 #pragma once
 
+#include <map>
+#include <iostream>
 #include "../math.hpp"
-#include <set>
+#include "../UsefulException.hpp"
+#include "../Mono/Mono.hpp"
 
-class GameObject {
+class GameObject;
+
+class Component {
+    Mono::ObjectHandle object_handle;
+    GameObject* owner;
 public:
-    Vec2 scale = { 1, 1 };
-    Vec2 position;
-    angle_t rotation;
-
-private:
-    // std::set<Component> components;
+    inline Component(Mono::Object managed_obj, GameObject* owner) 
+        : object_handle(managed_obj), owner(owner) {}
 };
 
+struct Transform {
+    Vec2 scale = { 1, 1 };
+    Vec2 position = { 0, 0 };
+    angle_t rotation = 0;
+};
+
+std::ostream& operator<<(std::ostream& s, Transform& t);
+
+
+class GameObject {
+    Transform transform;
+    std::map<std::u16string, Component> components;
+    Mono::ObjectHandle object_handle;
+    GameObject* parent;
+public:
+    GameObject(Mono::Object managed_obj, GameObject* parent);
+    
+    GameObject& operator=(GameObject&& o);
+
+    inline Transform& getTransform(){ return transform; }
+    bool tryGetComponent(const std::u16string& name, Component** out_component);
+    bool tryAddComponent(const std::u16string& name, Component&& component);
+};
diff --git a/src/Game/GameObjectPool.cpp b/src/Game/GameObjectPool.cpp
new file mode 100644
index 0000000..5a08b8a
--- /dev/null
+++ b/src/Game/GameObjectPool.cpp
@@ -0,0 +1,127 @@
+#include "GameObjectPool.hpp"
+#include <bit>
+#include <cstring>
+
+GameObjectPool::GameObjectPool(u32 size)
+{
+    useful_assert(size % 64 == 0, "size of GameObjectPool must be a multiple of 64");
+    this->size = size; 
+    first_unused_index = 0;
+    buffer = new char[size*sizeof(GameObject)];
+    used_indices = new u64[size/64];
+    std::memset(buffer, 0, size*sizeof(GameObject));
+    std::memset(used_indices, 0, size/8);
+}
+
+GameObjectPool::~GameObjectPool()
+{
+    // int i = 0;
+    for(auto&& p : *this){
+        // std::cout<<"~GameObjectPool i="<<i++<<std::endl;
+        p.second.~GameObject();
+    }
+    delete (char*)buffer;
+    delete used_indices;
+}
+
+bool GameObjectPool::isIndexUsed(u32 index)
+{
+    return ( used_indices[index/64] & (1<<(index%64)) ) != 0;
+}
+
+u32 GameObjectPool::getNearestUnusedIndex(u32 startIndex)
+{
+    if(startIndex >= size)
+        return -1;
+    if(!isIndexUsed(startIndex))
+        return startIndex;
+    
+    u32 i = startIndex/64;
+    // mark previous bits as used
+    u64 u = used_indices[i] | ( (1<<startIndex%64) -1 );
+    while(u == u64(-1)){
+        i++;
+        if(i == size/64)
+            return -1;
+        u = used_indices[i];
+    }
+    u32 bitpos = std::countr_one(u);
+    if(bitpos == 64)
+        return -1;
+    u32 index = i*64 + bitpos;
+    return index;
+}
+
+u32 GameObjectPool::getNearestUsedIndex(u32 startIndex)
+{
+    if(startIndex >= size)
+        return -1;
+    if(isIndexUsed(startIndex))
+        return startIndex;
+    
+    u32 i = startIndex/64;
+    // mark previous bits as unused
+    u64 u = used_indices[i] & !( (1<<startIndex%64) -1 );
+    while(u == 0){
+        i++;
+        if(i == size/64)
+            return -1;
+        u = used_indices[i];
+    }
+    u32 bitpos = std::countr_zero(u);
+    if(bitpos == 64)
+        return -1;
+    u32 index = i*64 + bitpos;
+    return index;
+}
+
+GameObject& GameObjectPool::get(u32 index)
+{
+    if(index >= size)
+        throw UsefulException(format("index %i is out of size %i", index, size));
+    if(!isIndexUsed(index))
+        throw UsefulException(format("there is no object at index %i", index));
+    return ((GameObject*)buffer)[index];
+}
+
+std::pair<u32, GameObject&> GameObjectPool::put_new(GameObject&& new_obj)
+{
+    u32 i = first_unused_index;
+    if(i == (u32)-1)
+        throw UsefulException("can't put new GameObject to GameObjectPool because it's full");
+    GameObject& r = ( ((GameObject*)buffer)[i] = std::move(new_obj) );
+    used_indices[i] |= 1<<(i%64); // mark index bit as used
+    first_unused_index = getNearestUnusedIndex(i+1);
+    return std::pair<u32, GameObject&>(i, r);
+}
+
+void GameObjectPool::remove(u32 index)
+{
+    if(index >= size)
+        throw UsefulException(format("index %i is out of size %i", index, size));
+    if(!isIndexUsed(index))
+        throw UsefulException(format("there is no object at index %i", index));
+    ((GameObject*)buffer)[index].~GameObject();
+    used_indices[index/64] ^= ~(1<<(index%64)); // mark index bit as unused
+    if(index < first_unused_index)
+        first_unused_index = index;
+}
+
+GameObjectPool::iterator::iterator(GameObjectPool* p, u32 index)
+    : p(p), index(index)
+{
+}
+
+std::pair<u32, GameObject&> GameObjectPool::iterator::operator*()
+{
+    if(index >= p->size)
+        throw UsefulException("can't get value of end() iterator");
+    GameObject& r = ((GameObject*)p->buffer)[index];
+    return  std::pair<u32, GameObject&>(index, r);
+}
+
+GameObjectPool::iterator& GameObjectPool::iterator::operator++()
+{
+    index = p->getNearestUsedIndex(index+1);
+    return *this;
+}
\ No newline at end of file
diff --git a/src/Game/GameObjectPool.hpp b/src/Game/GameObjectPool.hpp
new file mode 100644
index 0000000..c6c91c5
--- /dev/null
+++ b/src/Game/GameObjectPool.hpp
@@ -0,0 +1,37 @@
+#include "GameObject.hpp"
+
+class GameObjectPool {
+    void* buffer;
+    u64* used_indices;
+    u32 size;
+    u32 first_unused_index;
+
+    bool isIndexUsed(u32 index);
+    u32 getNearestUnusedIndex(u32 startIndex);
+    u32 getNearestUsedIndex(u32 startIndex);
+
+    friend class iterator;
+public:
+
+    ///@param size must be a multiple of 64
+    GameObjectPool(u32 size);
+    ~GameObjectPool();
+    GameObject& get(u32 index);
+    std::pair<u32, GameObject&> put_new(GameObject&& new_obj);
+    void remove(u32 index);
+
+    class iterator {
+        GameObjectPool* p;
+        u32 index = 0;
+    
+    public:
+        iterator(GameObjectPool* p, u32 index);
+        std::pair<u32, GameObject&> operator*();
+        iterator& operator++();
+        inline bool operator!=(const iterator& o) const { return index != o.index; };
+        inline bool operator==(const iterator& o) const { return index == o.index; };
+    };
+
+    inline iterator begin() { return iterator(this, 0); }
+    inline iterator end() { return iterator(this, -1); }
+};
diff --git a/src/Mono/Mono.hpp b/src/Mono/Mono.hpp
index 510ed65..11001c1 100644
--- a/src/Mono/Mono.hpp
+++ b/src/Mono/Mono.hpp
@@ -124,4 +124,25 @@ public:
     std::shared_ptr<Assembly> loadAssembly(const std::string& name);
 };
 
+class ObjectHandle {
+    Object object;
+    u32 gc_handle;
+public:
+    inline ObjectHandle(Object obj) : object(obj) { gc_handle = mono_gchandle_new(obj, false); }
+    inline ObjectHandle(const ObjectHandle& o) = delete;
+    inline ObjectHandle(ObjectHandle&& o) {
+        object = o.object;
+        gc_handle = o.gc_handle;
+        o.gc_handle = 0;
+    };
+    inline ObjectHandle& operator=(ObjectHandle&& o) {
+        object = o.object;
+        gc_handle = o.gc_handle;
+        o.gc_handle = 0;
+        return *this;
+    };
+    inline ~ObjectHandle() { if(gc_handle) mono_gchandle_free(gc_handle); }
+    inline Object getObject() { return object; }
+};
+
 }
diff --git a/src/UsefulException.hpp b/src/UsefulException.hpp
index 39955d6..d925ae7 100644
--- a/src/UsefulException.hpp
+++ b/src/UsefulException.hpp
@@ -18,4 +18,4 @@ public:
     virtual char const* what() const noexcept;
 };
 
-#define useful_assert(EXPR, ERRMSG) if(!EXPR) throw UsefulException(ERRMSG);
+#define useful_assert(EXPR, ERRMSG) if(!(EXPR)) throw UsefulException(ERRMSG);
diff --git a/src/main.cpp b/src/main.cpp
index 87e92ff..1d8be50 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,11 +1,15 @@
 #define SDL_MAIN_HANDLED
 #include <iostream>
+#include <iomanip>
 #include "GUI/MainWindow.hpp"
 #include "Resources/Resources.hpp"
 #include "Game/Scene.hpp"
 #include "format.hpp"
 #include "UsefulException.hpp"
 #include "Mono/Mono.hpp"
+#include "Game/GameObjectPool.hpp"
+#include <bitset>
+#include <bit>
 
 using namespace ougge;
 
@@ -24,15 +28,24 @@ int main(int argc, const char** argv){
         
         Mono::RuntimeJIT mono;
         std::cout<<"initialized mono jit runtime"<<std::endl;
+        GameObjectPool p(64*512);
 
         auto a = mono.loadAssembly("Ougge.dll");
-        auto c = a->getClass("Ougge", "ExampleScript");
-        auto scriptInstance = mono_object_new(mono.getDomain(), c);
-        mono_runtime_object_init(scriptInstance);
-        auto scriptUpdate = Mono::Method<void(f64)>(c, "Update");
-        updateCallbacks.push_back([scriptInstance, scriptUpdate](f64 deltaTime) -> void {
-            scriptUpdate(scriptInstance, deltaTime); 
-        });
+        auto gameObjectClass = a->getClass("Ougge", "GameObject");
+        for(int i = 0; i < 32*1024; i++){
+            Mono::Object gameObjectManaged = mono_object_new(mono.getDomain(), gameObjectClass);
+            p.put_new(GameObject(gameObjectManaged, nullptr));
+            GameObject& o = p.get(0);
+            std::cout<<'['<<i<<"] "<<o.getTransform()<<std::endl;
+        }
+        return 0;
+
+        
+        // mono_runtime_object_init(scriptInstance);
+        // auto scriptUpdate = Mono::Method<void(f64)>(c, "Update");
+        // updateCallbacks.push_back([scriptInstance, scriptUpdate](f64 deltaTime) -> void {
+        //     scriptUpdate(scriptInstance, deltaTime); 
+        // });
 
         GUI::MainWindow w;
         w.open("ougge", update);