very rough platformer demo

Source/Demos/Platformer/Systems/PlayerSystem.cs

@@ -0,0 +1,35 @@
+using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Input;
+using MonoGame.Extended.Entities;
+using Platformer.Components;
+
+namespace Platformer.Systems
+{
+    [Aspect(AspectType.All, typeof(VelocityComponent), typeof(PlayerComponent))]
+    [EntitySystem(GameLoopType.Update, Layer = 0)]
+    public class PlayerSystem : EntityProcessingSystem
+    {
+        private readonly KeyboardInputService _inputService;
+
+        public PlayerSystem(KeyboardInputService inputService)
+        {
+            _inputService = inputService;
+        }
+
+        protected override void Process(GameTime gameTime, Entity entity)
+        {
+            var movement = entity.Get<VelocityComponent>();
+
+            movement.Velocity = new Vector2(0, movement.Velocity.Y);
+
+            if (_inputService.IsKeyDown(Keys.Left) || _inputService.IsKeyDown(Keys.A))
+                movement.Velocity = new Vector2(-260, movement.Velocity.Y);
+
+            if (_inputService.IsKeyDown(Keys.Right) || _inputService.IsKeyDown(Keys.D))
+                movement.Velocity = new Vector2(260, movement.Velocity.Y);
+
+            if (_inputService.IsKeyTapped(Keys.Up) || _inputService.IsKeyTapped(Keys.W))
+                movement.Velocity = new Vector2(movement.Velocity.X, -600);
+        }
+    }
+}