Good first effort; needs more mechanics
It's a good first effort (particularly with the shop and house), and it's a good base idea to work with for a more complex game. For example, if you were to turn this into, say, a ninjaball, you could add momentum to the ball.
This is easy - you just have separate mx and my numbers that start at 0. For every frame you multiply those numbers by, say, 0.99, to cause the ball to slow down. If the player holds down left, then decrease mx by 10. Now you apply that to the position of the ball by adding the momentum to the current position. If the ball hits the edge of the field, then simply negate the momentum (mx = -mx) so it bounces.
The next step after that is to have the ball follow the mouse (either pulling the ball towards the pointer or using mouse movement itself as "pushing" the ball in the direction you move it). This is easier than keyboard control, much more involving for the player, and allows the game to become much more complex and frantic.
After that, you could add more obstacles and loot. You might have things to avoid, or enemies you need to hit hard enough to destroy. A few more mechanics like that, and you have the classic game Oxyd!