My my my, first off some tips for newer players: To climb walls faster jump [Hit S or Z] while going upwards with your arrow key, this becomes much easier when you receive the first ability. Don't give up on the game the level of difficulty increases but there is no selected order for you to complete the puzzles so have fun.
About the game; Music and Atmosphere: 10/10 the birds chirping add a zest reminds you that you're still alive.
Background; Amazingly serene.
Controls: Fluid; point to consider a triple jump might dampen the spike in difficulty but I loved the challenge.
Final Thoughts: This had a real Cave Story feel the nostalgia hit me like a truck this was an amazing game and I'd love to see more from you.