Thank you very much for the feedback we are happy you enjoyed! The rebound mechanic is something we are definitely working on, 45 degree angles sounds like a pretty awesome idea. the bullet rebound itself is seemingly controlled by distance/height from block, but we don't really know exactly it works, Will definitely be putting more tests towards it!
More levels are defiantly on the drawing board. the first thing we are currently doing is making a better UI, one that can be transferred much easier than what we currently have, then we can go pretty wild on the levels.
I will be taking note of the jump firing problem and exploring ways to fix it
Thanks again for the feedback!