I got stuck on level 2, until I... didn't. I think that the issue may be with the bullet hitbox "skipping over" the target hurtbox (since when it does work, it looks like it passes through what would be the corner of the hurtbox). It would have been cool to, instead of the levels having more varied walls statically placed, those were added to the player's "toolbox" of ways to interact. But still, a really interesting design!