Dirty Balloons.

Because only the Balloon will be moving, we only need to change a small part of the screen each frame. Luckily pygame handles this nicely.

Efficient screen updates with dirty rects, DirtySprite and LayeredDirty. When an object

See Quick & Dirty: Using Pygame's DirtySprite & LayeredDirty (A tutorial) for more information about pygame dirty rectangle sprites.

Now I have the basic game objects in place.

Well... they are still 'programmer art'.
The Balloon a green square, and the background just a flat blue or red so far.

Basic game objects in place

The resolution I've decided on is 640x480.

I plan to draw them all by hand at this stage, and that should make the asset creation easier.

This means 320x480 for each side.

Maybe it would be fun to draw a different city for each 'level'. So on the left there would be Paris, and on the right London.

And the player has to move both Balloons through the city safely. But they only have one controller for both the Balloons!