Thanks for the detailed review, I appreciate that. I'll check on those points you've mentioned.
Regarding that level you are sharing, you can step over the enemies once they are frozen, so the idea would be to jump on the neareast enemy to go ver the platform on the right. Then there calculate the shoot to freeze the enemy behing the wall. You need to freeze both enemies to win the level. The gun going over the wall is a bug, the idea is that you are not able to shoot to the second enemy from there.