This game was great fun to play, though I could't figure out how to get past level 12.
I have tried something like this before, could you show the code to get the bullet bouncing off the wall?
Have you ever played Portal / Portal 2? Gotta use those portal mechanics! The chain block you can see up the top does not allow bullets past however allows the player past (like the opposite of glass)
As for the code for the bullet bouncing, its really simple! When the bullet is instantiated, I set its initial velocity, and the rest is physics! On the rigidbody2d the bullet has a gravity modifier of 0, 0 of any drag, and its collider has a physics2d material which has 0 friction and 1 bounciness. To make the bullet always point forwards, thats just a matter or rotating it to face its direction of motion.