TF2. It's basically got the same game modes as TF2 too. Push a cart thru a level, capture points, etc. But the heroes all play like a mix between standard FPS characters (there's just a regular ass, assault rifle soldier man), most of the TF2 classes (there's a hero that plays like every TF2 class except for Spy that I can tell) and MOBA/Dota heroes. The dude I like playing the most so far is basically pudge. He's got a hook and a shotgun.
Aside from hero abilities, there's no MOBA elements, like MNC. No creeps, no tower defense type stuff. You can change your hero mid-match, which is very un-MOBA like. A part of me really wishes it played more like a MOBA. I think it would be more fun if you locked in heroes in a team v. team game without asymmetrical objectives. I hope they haven't ruled out a mode like that for the future. But on the other hand, it's actually just a lot of fun to jump into a match and have it be over within 10 minutes. MOBAs take too much god damned commitment. So this has the brevity and satisfaction of just playing a regular-ass, competitive FPS, but the variety of being able to play a bunch of different types of characters. Team comp still matters a lot. If you don't have a balanced of all the different types and use your abilities (specifically your ultimates) well, you can get fucked pretty good.