So on part 4.
The gimmic on map 11 was decent and intresting.
Having breather levels to explain mechanics in a safe area was fine. However some changes
1) Make an easy lvl where you hvae to split up to handle things to introduce player to the idea. Remark that chairs can be used to rest.
2) The final challenge should probally by split in 2 with checkpoints or so. I didn't know you needed to take out the enemies to get a key. And this ensured i had to redo so much because i missed it. Ethier remark it on a map anaylase cutscene at start. Or make it clear.
3) Great idea needs a bit of polish. Overall enjoying it a lot