wow.. I only read the first page of comments from Steam.. but I can't believe how many people are commenting critically.. you have some serious buzz.. maybe not the buzz you want, but people are talking about your game! so, even though things might seem negative, you can spin this around...
as for the art... don't change your art style! I'm no artist (I dabble) and I consider myself more of a producer-type. but your art seems good to me, I mean, what the hell is "good" anyway? Art can be whatever. If you have confidence in it.. just be like.. "hey, here's my art.." who cares what people say.. they'll look like idiots when your game does awesome and everyone starts copying your art style... I mean, does it look amateur? I don't know.. who cares.. if it does.. that's the games look.. just stick with it and trust in what you can do. Yes, things look bad when you try to do things you aren't really good at.. this is true for anything art related. So just do what you can do... Consider a high school kid that draws in his/her notebook all day.. say that art is "subpar".. but you make a game out of that art.. that would be so cool.. so who cares if it's "good"!
Now your animation seems to need a little work... just get an animator involved.. find an animation student or something. They can even just fix the current animations you have. Also things like how the character transitions from left to right doesn't look great...almost like you cut some corners (you probably didn't but that's what it looks like).. . the stopping and starting.. I would try to get that tightened up and smoothed out. It will only help your art style..
The other art comment is.. I'm not sure what it is.. but the characters seem to be "on-top of the background. It doesn't look like they sit in the environment really.. not sure if that is your "line quality" (too much outline) or shading.. I don't know.. but they feel kind of paper thin... maybe you can change the line quality (at least on the edges of the sprite).
I think also your willingness to be open about who you are what you are all about is opening you up as well.. I don't think it's a bad thing..but I would not respond to negative comments... that's just pulling you into a direction you won't be able to return from.. ala Phil Fish...
seriously good luck.. I think you need to just find confidence and also try to distance yourself from the game itself. The game isn't "you" so don't be offended by anything. It's hard to be so close to something and look at it with an objective eye. Gamedev is a long and winding road of learning...