This was a really solid 2d platformer. I was kind of confused on my goal for the game. Collecting gems and diamonds didn't really do much for me as far as I could tell. I didn't have time to play all the way through so that may have helped explain everything. The controls worked fairly well. The only issue I noticed was the ground detection was a little wonky especially on moving platforms. This would cause my character not to jump even if I was rapidly pressing the jump button. Also I didn't notice any coyote /hang time, which is when you start walking off the edge and the player can still jump even if technically not grounded. A simple timer delay after a player is no longer "grounded" can really help with this. Overall, the visuals, and gameplay were solid. Nice work! Keep up the gamedev dream!