There are a few things about the physics of lbreakout2 which drive me crazy.
I believe the main one is the complete and total lack of inertia... After hitting a brick, the ball shouldn't bounce off in any random direction at full speed. It should be slightly thrown off it's straight path, but otherwise continue on, or at least get slowed down when it completely changes direction. Right now, the ball feels super spring-loaded.
Another is the lack of randomization. It's all too easy to get the ball into a corner, and have it get stuck in an infinite loop, boncing off of the exact same spot on the walls and paddle. In the physcical world, there is a lot more randomization when a ball bounces off of a wall.
It's those two missing features that make me want to throw the mouse through the screen in frustration, rather than play... I hope this will be improved in future versions.