http://24.media.tumblr.com/tumblr_m521zrtftm1qmaa05o1_500.jpg

http://www.sharenator.com/Master_Chief/#img-30892

I think the arcade gameplay is really good if played at a challenging difficulty level. It would be difficult to explain without writing a book but I could show you in couple minutes of coop. :) The game is 99% action though so if that's not your cup of tea you'll be underwhelmed.

this is the game that made two weapon limit and regenarating health popular.One great step for console FPS,one hundred steps back for FPS on Pc.

Well having limited health on a game like Halo would be a Death Sentence because the AI in those games are so aggresive its impossible not to avoid many hits. And the fact that its a game where enemies fire guns on you. Old School PC FPS has alot of Enemies that attack up close and personal like savage monsters. Doom is an example where you can memorize the monsters paterns especially the Imp's fireball, but Halo the Covenant has no Patterns they are Unpredictable. You think a Grunt will just fire on you or Run away but than all of a sudden it pulls out 2 plasma grenade and charges at you like a suicide bomber.