i played through the demo, and i liked it, i love platformers to begin with !
The platforming feel feels good, the jumping is alright, although it feels like the gravity is just a little too low because it feels just a little too slow to land from a random jump to get up a platform, and the art style, it's unique to my knowledge, but the background doesn't really meld well with the constant neon NPC's, enemies and the player, i think looking at old NES games could give you an idea how to make enemies and players stand out more against a more detailed background, not even really, just something more simple and easy to look at. i like the enemies a lot, nice variety and i like the way the moving enemies are consistent and easy to remember, the boss is also nice, i'm not a great fan of gimmick bosses but it's allright.
The sword is nice, it's fast and responsive, as good as it can get.
the pet is okay, i called him cumquat, he reminded me of the color orange, his Attacks and the way he goes nuts is kinda cool because he's an ANIMAL ! but it's also bothersome at this point.
Jumping on enemies is just so much fun, i love it so much.
sometimes there's platform segments setup to act like a mario game, you go fast and you automatically killing stuff whilest you feel in controll, unlike a sonic game.
So in the end, i liked it, it's very promising, the only things that doesn't really sit with me is the graphic style/background, but i feel that's largely my problem.
(P.S. This is my personal opinion of the game, i mean not to tell anyone what to do, please remember no one can live your life but you, AKA my opinion doesn't have to matter, just want to put that out there, sorry.)