Game is very cool, but it lacks content, after few hours everything seems boring and repeated-same enemies,worlds,loadouts,items etc. Game workshop is not very... rich, in content so its hard to get any additional fun, sure there are missions to complete, some are very hard and are a challenge but there is nothing new when it comes to those missions...
I hope that game is NOT a 'finished product' and new, hopefuly enormous updates are incoming, I would even buy dlc for this game (beside pure cosmetics like skins)