Thanks for giving it a try!
Wall jumps were remade, update is live.
Checkpoints - after some considerations we came to conclusion, that rn it's impossible to implement since it's not clear what to reset after restarting from checkpoint. Looking into redesigning levels themselves.
Floating orbs - they're just collectibles for completionists, they give no bonuses/don't unlock anything. Ending screen shows how many out of total collectibles player found.