This is the only game that has ever given me headaches.
First it is a 1st-person shooter. Second it requires some skillful platform playing. Third there were few saving points and a limited amount of lives. Combining these three aspects, one would think that it would make for a great game. Well somewhere the "great" was lost, maybe it was overkill. I think of it as a "great" stepping stone in the evolution of games. Like a 2nd cousin to Doom or a great uncle to Halo.
For me to finish the game, I had to rely on using cheat codes. A very sell-out way of finishing; it was just too tough for me. Really if it weren't for the headache-inducing ability of the game, I think it really would a better game.