This is the most fun I've had with shooters in a long, long time. It's just pure carnage that never lets up. The levels are interesting and each has different objectives to prevent the killing from getting stale. The upgrade system is fantastic too. The buffs each upgrade gives you are huge so you end up flying around the levels at ridiculous speeds within a few missions. The full game is about 3-4 hours long on normal mode so it doesn't last long enough to get boring. If it wasn't for the XCOM name people would have loved this.