I see you have problems with the tiles, you need to either set up the editor or manually them so that they have the side of the square a pixel shorter, so you avoid those weird visual artifacts.

On the type of gameplay I suggest you make the controls more responsive by increasing the speed or lateral force applied with the controls and smoothing it with some smoothing method of your choice.  There is a point in the middle of the first level where there is nothing that is supposed to hurt or kill Santa but he dies. So I guess I don't understand something

Hmm. It needs some polishing I think you can agree but else its a solid game. But there is one thing and that is that I get reset somehow after the first big mushroom thing.