This came out of left field. Heard of it thanks to Steam putting it on its store front page yesterday, gave it a go with a friend for two hours or so. The whole leveling up, upgrades, powers, weapons thing doesn't feel very intuitive, lots of menus within menus and not a whole lot of explanation. Gameplay itself doesn't seem like anything new or meaningful, point and shoot with only two weapons (plus the melee one); but hey, weapon spread is minimal, hitboxes are generous, there's some decent hit feedback. The level design, generic as it might be visually speaking, has a fair amount of variation when it comes to the shapes used, heights, pathways and cover.
The enemies weren't too interesting. For the most part I only noticed three archetypes: big guy in armor using ranged weapons, smaller guy trying to melee you with a spinning blade thing, and shield dude. I think there were different kinds of ranged dudes, but they all seemed so sameish in their looks and abilities it was a wash. In two hours (about six or seven missions) we only fought one boss and while I managed to miss that fight entirely, the cutscene made it look like he was just a regular-sized dude.
I liked the way once you get going your squad persists through missions and how it let you choose what to do next with votes. Between that and the way mission objectives are trimmed down to following the next marker on the minimap, it's easy to pick up and join in, very accessible. Couldn't notice any lag either, be it Internet related or local, smooth as silk.
It gets repetitive quick and I'm not sure I will ever play it again, kind of lacks something to hook me up (although sliding and shooting is fun). Can't really complain about anything for that price, though. Hopefully this succeeds commercially, it's always nice to see more co-op oriented shooters, and if this F2P thing works out for them and starts a trend I certainly wouldn't mind.