Pretty simple game, I can see what you're going for.
- I would say maybe move the ghost to the far left of the screen so that the player can have more time to react (or just fill/remove the open space, since you can't move back there you don't need to see what's behind you.)
- I would also make the spikes a little more distinct from the background, either with a different color or a strong outline, just so that they blend into the background less.
- Some variation might make the game more interesting. Maybe an item that gives you an extra heart, or an invincibility item or something. Or the spikes/background changing color after getting a certain score.