Hi ! Pretty interesting game. Reminds me of the old marble mazes from my childhood ^^.
Just a few advises to improve your game:
- The end is not visible when we reach the last platform, so it took me two tries to reach it.
- You should add some sound design, a sound when the ball touches a new surface, another one when you touch a red block and finally one when you reach the goal. You can record your own sounds, take some free sounds on the internet (check their license!) or use a soft like sfxr (it's free!) to generates them in no time!
- It could be cool to add some effects when you touch a red block or the final yellow block: a shaky cam, a particle effect, etc. to increase their impact.
- Finally, you can work with lights to make your scene prettier even if it only contains cubes and a sphere!
By adding some sound design and feedback, you could greatly improve the game feel and make the experience more enjoyable ^^