Wow, this was much more fun than I expected. To be honest, the instructions contained a lot of 'technical' stuff that players would naturally learn from just playing the game, stuff that doesn't need to be told out loud. I think all you really needed to say is that the dice blocks disappear under your feet and you have to collect all keys on a floor to unlock the next one and players would figure out the rest on their own.
The biggest drawback gameplay-wise was, I think, the floatiness of the character. It was simply difficult to control. GMTK and Jonas Tyroller have some good videos on platformer design and how to balance all those variables. (My secret formula as 0.5 pixels/tick squared acceleration and 5 pixels/tick max speed.) In addition to that, coyote time, variable jump height, yada yada.
But if you improved that and the presentation, added a bit more juice, this could be an easy 4-5 stars. Well done.