I think it could be good if you continue working on it, but so far it's just bare bones with some problems.
– The camera doesn't catch up with you which means you are constantly running close to the right edge of the screen. And you are so fast there's almost no time to react to possible danger. I guarantee you everybody who played this game for the first time died by running into the first zombie.
One time I even encountered a bug when a zombie supposedly killed me (the camera stopped following me), but I didn't die and could move around fine.
Also, there's no need to fill 50% of the screen with the ground - I'd much rather see what's above me.
– The controls for a platformer game have to be really good, but they feel a bit stiff.
For instance, you have no control of your jump. It's always the same arch. Take an example from Mario - there's some standard jump (going right and jumping), then a long jump (running right and jumping), but you can also slow down mid-air or even jump backwards a bit (jumping and pressing/holding left mid-air).
In this game you can't really make precise jumps, you often have to go back a bit to be able to jump to the exact spot you want. E.g. you jump forward more than up, so if there's a zombie right next to you, you die by ramming yourself into it.
– I don't know what the blue blob is, but if it's there to prevent you from going too much to the right (and almost always kill you), then there are better ways to do it (e.g. a huge rock in your way).
– Sometimes if you land on a zombie's head, it doesn't kill you, but as soon as it swipes it arms, you are dead. Either it should kill you right away, or not at all.
Also, the purple hair zombie is harmless.
– I don't think the idle animation is necessary. If you run somewhere and make a tiny pauses for the camera to catch up to you (or to wait for the zombie), the cat slowly reverts to it's idle state every time.
– If you are going for a spooky atmosphere, a rotating cat flying off the screen spoils it a bit (main character's death in a horror should be scary, not comedic).
– The game probably should restart by itself, not wait for you to press R.
– If a zombie falls from a ledge, it doesn't fall nearly as fast as the cat (→ inconsistent gravity).
Having said that, I can see the potential in this game. The spooky atmosphere is done quite right (also pretty well supported by the music), the cat's moving animation looks good and the snowing is a nice addition.