Nice graphics. Clear instructions. The spaceship is easy to control but I would have preferred if there was more continuous movement of the ship. There is a pretty heavy deceleration as soon as you release the thrust and the ship comes to a halt quite quickly. Another thing which could probably be improved is the left and right screen edge collisions where both horizontal and vertical movement is blocked. I think it would feel better to only limit horizontal movement and let the player slide vertically along the left and right edge of the screen (i.e. only restricting movement horizontally but keeping any vertical movement).