You're not missing out on anything, the beauty of this game is only skin deep. The only thing thats remembered about this game is it's graphics. As you've probably already gathered judging by this thread.
I played through it multiple times and still enjoy the AI (both human and alien) and open ended approach to encounters (including geographically) that few games even today do as well IMO. Real-time weapon customization and the level of interactivity to everything combined with the tools of the nanosuit makes every playthrough feel fresh because it allows so many different styles of play.
I'd much rather play through Crysis 1 again than 2 or 3. Those were truly forgettable in a sea of "military shooter" mechanic driven blandness.