I like it! It's really simple, but in a good way, with a lot of details in the terrain, which makes it fun to explore, the collectables feel rewarding and give you a bit of purpose to the exploration and a sense of progress. There are some minor things I would fix, like the character speed is silly fast, there are some smaller rocks hanging in the air just above the ground and I think there were no collisions on one of the bridges, but overall I really liked your level design, it's very creative and I'd definitely play full game like this, with more gameplay and story and the collectables being just an addition :) Good job!