Excellent!
i did not expect much from this game from trailers ive watched and the demo i played but i must say i was pleasantly surprised. Its great mindless fun, they took a lot of gameplay inspirations from doom instead of coming up with new idea which isnt a bad thing in my opinion ( if it aint broke dont fix it) plus the unique weapons and mechanics they added are great fun so its not like the game is just a doom clone.
I must give major props to the exellent level desing, although open and complex it always leads the player in the right directing ( not counting a few instances where for some reason they put a button on a high ceiling that you need to shoot and cant see unless you are standing right under it) the level design also does a great job at telling a story through the levels with enemy placements, events etc.
With all that being said i did run into a few glitches that made me restart my game to fix here and there but other than that it was a great experience that is just the right length and its pretty cheap too.