I've been a fan of Halo as long as I can remember and a big fan of Destiny as well, it's surprising how much DNA of those two games can be found directly in Marathon. Honestly I can't believe it took me so long to play it. The story and world are fantastic, much more philosophical than Halo's near-superhero action and Destiny's fantasy and magic, but still grounded and human in the way those games are. It hasn't aged perfectly on all fronts, which is to be expected from a shooter that released over 30 years ago, but it's still a game I think every shooter fan should play at least once.