Because you should, its amazing, and free.
The concept is basically the game I’ve been working on in my free time (top down shooter with character progression and online co-op), but they basically crushed my hopes and dreams by making probably the best top down shooter ever, and releasing it for FREE, bastards! But I’ve gotta give it to them, it is fantastic.
I played last week and it is very nice.
I am also planning to make a top down shooter, would not exacly the same, and I think it is fine to have more top down shooter on market.
That is a bummer, maybe you could make yours web playable.
Playing it every now and then on Steam and must say it`s an incredible game so far. Feel free to add me on steam as brokenpoly, so maybe we can hook up and play sometime 
uhhhhhhhh i played it it sucks nobody talks in the game i cant join other peoples games i can only host my own for some reason also i cant figure out how tot talk in game i deleted it 2 days after install but the game/gameplay itself was awesome i particualarly liked the graphics
Ok, I’ve played and disagree with devilkingx.
People talk frequently in-game, I can join other games (Although I do prefer to be host), and you can look at the control options to find out what is what.
Gameplay is intense, and can be very fun when you’re swarmed.
I’d recomended downloading and giving it a try 
Been playing it a bit since it came out, really nice game, hope they add more levels soon though! 8)