ok, i just (tried) playing it, and i'm afraid i'm going to have to give it a dnf, purely because of the sheer amount of lAG!
pros:
good use of entities
i liked the style
good choice of weapon
i liked the puzzle element
cons:
LAG LAG LAG LAG LAG LAG LAG
unfortunately i could not finish the game because it was so laggy!
you have massive outdoor and indoor levels, and i'm afraid the fps creator engine just cannot cope with that, even on the best computers.
nazi's? make better enimies!
to solve your lag problem: try compressing your levels a little bit, and maybe make indoor and outdoor two different levels.
don't set things to always active, that can really lag up the engine.
basically try to tone your levels down a bit.
other than that, well done!
the onion mind probes are coming for your soul...
they take your humanity... and give you...
onionity.