Overall, I think this could make for a great mobile game that would sell reasonably well.
Its main flaw is that it has unfair difficulty. By unfair I mean were the player doesn't feel its his/her fault. People complain about the red squares because the yellow one is too hard to control so not dying starts involving luck mostly and the player feels he/she lacks agency.
I think the yellow square should instantly move at a predefined speed instead of gradually accelerating. This allows you to change direction quickly and predictably and I think will work better for this kind of game.
http://www.emanueleferonato.com/2012/05/24/the-guide-to-implementing-2d-platformers/ (scroll down to "Acceleration") .
Another thing I noticed is that I end up not moving the platform at all. Maybe focusing on the platform, the yellow square and the red squares is too much, but with better controls I think it'll be possible to stay alive without having to move the platform, and moving the platform can become an emergency-only pro technique.
Also another thing that feels unfair is letting the character go off-screen. You can be hit by red squares and you can't see them. I think the main character should not be able to go-off screen.
Other than that, I think the basic gameplay elements are really fun.