There's a few good ideas in this game, but the biggest problem is the jump.
It is such an important feature in this game, as it is the only way to evade enemies, but it doesn't feel good. The character barely stays in the air, and momentum is very linear, requiring you to be extremely precise if you want to jump over enemies.
One thing I really like is the Black and White thing. Enemies can walk over (and in the case of one level, hide behind) black tiles while you phase through them. You could probably make a whole game that utilizes this concept more.