It makes more sense for Component to be an interface

core/src/com/me/asteroids/components/AccelerationComponent.java

@@ -3,7 +3,7 @@ package com.me.asteroids.components;
 import com.badlogic.gdx.math.Vector2;
 import com.me.common.ecs.Component;
 
-public class AccelerationComponent extends Component {
+public class AccelerationComponent implements Component {
 
     public Vector2 acceleration;
 

core/src/com/me/asteroids/components/ModelComponent.java

@@ -4,7 +4,7 @@ import com.badlogic.gdx.math.Polygon;
 import com.badlogic.gdx.math.Rectangle;
 import com.me.common.ecs.Component;
 
-public class ModelComponent extends Component {
+public class ModelComponent implements Component {
 
     public Polygon model;
     public Rectangle aabb;

core/src/com/me/asteroids/components/PlayerComponent.java

@@ -2,6 +2,6 @@ package com.me.asteroids.components;
 
 import com.me.common.ecs.Component;
 
-public class PlayerComponent extends Component {
+public class PlayerComponent implements Component {
     // TODO: implement engine feature for tagging entities (as player, for e.g.)
 }

core/src/com/me/asteroids/components/PositionComponent.java

@@ -3,7 +3,7 @@ package com.me.asteroids.components;
 import com.badlogic.gdx.math.Vector2;
 import com.me.common.ecs.Component;
 
-public class PositionComponent extends Component {
+public class PositionComponent implements Component {
 
     public Vector2 position;
     public float rotation;

core/src/com/me/asteroids/components/VelocityComponent.java

@@ -3,7 +3,7 @@ package com.me.asteroids.components;
 import com.badlogic.gdx.math.Vector2;
 import com.me.common.ecs.Component;
 
-public class VelocityComponent extends Component {
+public class VelocityComponent implements Component {
 
     public Vector2 velocity;
     public float maxVelocity;

core/src/com/me/common/ecs/Component.java

@@ -1,5 +1,5 @@
 package com.me.common.ecs;
 
-public abstract class Component {
+public interface Component {
 
 }