Proxy Blade Zero is a simple yet satisfying robot swordfighting game that rewards quick reaction times and knowing when your attack opportunities are open (this aspect feels similar to melee combat in the Souls games - at least for me - as most of the time you can't just run in and mash the attack button). The combat feels good and pulling off a good string of attacks/dodges without being hit is challenging, yet fun. New enemy types have appeared frequently, enemy groups are nicely varied and it doesn't pull many cheap tricks either. Music is great, fits the tone of the gameplay very well and the visuals are done well too. It's not the most detailed look in the world but the animations are good, the robots look good and the lighting/attack effects have a bright, vivid design. If you think this game isn't worth $7 ($5.60 on sale) because of the way it looks then you're a baby, in a big budget cinematic game it's fine to expect top of the line visuals because the story and graphics have to make up for the linear, rote gameplay. This isn't one of those, it's a gameplay focused game. There's no filler, it's just you and the other robots trying to kill you. The only negative I can really think of is the length. Granted there is hard mode and the combat could warrant another playthrough so you'll definitely get your money's worth. Also there are too many pointless achievements (beat a mandatory level, kill 50 of X enemy, dodge 100 times etc).
I'm sort of disappointed in the amount of boss battles but it's nothing big, it's just that with how fun they were I would have loved to see more of them. Loved the voice acting and filters though, they fit perfectly, weren't too cheesy or trying to be funny and gave the bosses some personality. I'd personally buy a sequel or expansion with more stuff day one if that ever came about.
I played this on an f310 controller, I can't comment on how it plays with kb+m.