Interesting, but not very entertaining. Most of the time just standing in front of somthing, hitting down and waiting. Health upgrades were useless, couse i got hit one time in the entire game. Same goes for weapons, just decided to wait until the last weapon and killed everything with the sniper. ofcourse with fast reaload, but still. Maybe even the handgun would have been enough.
It lacks some challenge, even the final fight is easy. Just stand there and shoot in one direction.