I've got collision detection working, so the ball can now collide with bricks, the walls and the paddle. There's a few small kinks that I'll need to debug (the ball sometimes missed a corner hit due to a flaw in the algorithm) but it's reasonably playable as it is. I've also redid the graphics, going for something that looks good in a small window over a full screen look.
With a few days left I now need to start thinking about what gameplay I want to put into Brixtar. It's been a while since I've played an Arkanoid/Breakout clone so I'm not sure what features are considered standard. I'll need to include some powerups and more than one level. I should also include some different brick types - currently all of the bricks are worth the same points and get destroyed in one hit. I'll also need to put in sound effects and music, and a menu too.