I've played Spartan Assault and it's a pretty decent game. You can't compare it to the main Halo titles because it was originally a limited mobile game anyways. I had fun for a few hours and easily maxed out the achievements in the game and beat it. I wouldn't mind playing it over again from time to time, and parts of the game are somewhat challenging. The limited multiplayer co-op missions are pretty fun and chaotic. A lot of people won't enjoy this game that much because they'll spend too much time comparing it to the main Halo games. However, it's still decent enough for what it is.