I did test out or check out the game demo. I'd say it's pretty bringing up the classic theme like SEGA games or SNES games. The game also reminds me Sparkster and Knight Rocket the remake one.
When I wanna move the character, I did assume some of the obstacles were part of the background so I always get clumsy. Maybe there should be some lighting effects so can I tell what are the obstacles and the backgrounds.
I played the game until stage 2 only. I would suggest that don't make the players be lost like "where should I go". Because I did get frustrated that I couldn't advance more there. The first mini bosses in the first stage are kinda OK. Maybe you should add one more sound effect to tell that it's gonna "charge" or "ram" the character. About the hit detection, I could tell that "if I were you, I would slightly increase it.". Next, the enemies. There are some players might get mad at enemies that are hiding in the boxes. It's OK. But it's getting unfair since players are given with 3 health bars. Health with percentage system will make players less tired.
The fox character, the one that players will play as. It's all cute, yeah overall. I love the sound effects. all those stuff might let player to play carefully though.
That's all what I got from playing the game. I did enjoy it too, at least. :)
I hope for the better in the future. :D