diff --git a/src/2d.js b/src/2d.js
index cfe66fa..0cc7b3b 100644
--- a/src/2d.js
+++ b/src/2d.js
@@ -30,7 +30,7 @@ export class Circle {
 		b.o.addTo(v.adjust(b.r - bd));
 		return true;
 	}
-}
+};
 
 export class Vec2 {
 	constructor(x, y) {
@@ -120,4 +120,4 @@ export class Vec2 {
 	cross(y) {
 		return this.x * y.y - this.y * y.x;
 	}
-}
\ No newline at end of file
+};
\ No newline at end of file
diff --git a/src/components.js b/src/components.js
new file mode 100644
index 0000000..84af5b5
--- /dev/null
+++ b/src/components.js
@@ -0,0 +1,18 @@
+import { Circle } from '../src/2d.js';
+
+export class Motion {
+    constructor(p, v) {
+        this.position = p;
+        this.velocity = v;
+    }
+};
+
+export class CollisionBox {
+    constructor(r) {
+        this.r = r;
+    }
+
+    shape(o) {
+        return new Circle(o, this.r);
+    }
+};
\ No newline at end of file
diff --git a/src/main.js b/src/main.js
new file mode 100644
index 0000000..cb18c29
--- /dev/null
+++ b/src/main.js
@@ -0,0 +1,16 @@
+import { Vec2 } from '../src/2d.js';
+import { Motion, CollisionBox } from '../src/components.js';
+import { EntityRegistry } from '../src/ecs.js';
+
+function main() {
+    let registry = new EntityRegistry();
+    let tank = registry.create();
+    registry.assign(tank, new Motion(new Vec2(0, 0), new Vec2(1, 1)));
+    registry.assign(tank, new CollisionBox(1));
+    registry.forEach([Motion], (id, motion) => {
+        motion.position.addTo(motion.velocity);
+    });
+    console.log(`motion: ${JSON.stringify(registry.get(tank, Motion))}`);
+}
+
+main();
\ No newline at end of file