I bought this game because I had it on iOS. I have not seen any explanation for negative reviews, so I will put in my own input:
Unique Fighting Style
Black Border around Map
Ambiguous Quit Option
Overall, just like the iOS one, I think this is a great game. It is witty, fast paced, and allows for up to 4 players for an all out brawl. Unfortunately, it is distracting how levels are surrounded by a large black border, but I am testing this on a 3:2 ratio screen so it may vary on a 16:9 screen, in whcih case I will update the review if it turns out to be different. I do think that automatic scaling of levels would be in order though, and level editors would be nice too.
As there are very few games with local coop, and even fewer with controller support, this stands out as a great option for those Steam-Machine Users, but it also supports 4 players on a single keyboard, albeit it is a little strange.
This gives you a Smash Bros feel but in a rather different manner, You may find that the pigeon is useful for beginners with its homing ability, whereas other weapons like the knife are a very potent and accurate weapon. I am writing this reveiw based off of past experience with the game, and it does run at native 2160x1440 resolution at max graphics at 48-60fps on an i3-4010Y, which is very impressive optimization. Of course, the graphics are simple but clean.
I highly recommend this game, but if you have hesitations about this game due to other reviews that are not written, check out the iOS reviews and other game website reviews for this. I grabbed this at a 75% off sale making it a great value, the value at full price is gonna be more dependent on whether you have freinds to play with, as this is a solely multiplayer game.