Eh, it's okay.
Hint: generally, it's better to try to introduce players to new mechanics in safe environment. Otherwise, player having to guess e.g. what jumping robots do and dying because of something they couldn't predict, frustrates them.
Similarly, first encounter with chains (that I thought were just decorative background) screwed up my jump and made me die - for no fault of my own.
E.g. - compare how in Super Meat Boy in couple first levels you can SEE the buzzsaw obstacle, but you can't get hurt by it until level 6 - and before, player would encounter the buzzsaw in Warp Zone minigame level before that, letting them find out what it does, in a way that does not hinder them from continuing the game.
Also it's a good idea to ensure that player HAS to know all basic mechanics from the get go - I died multiple times in level 3 before realizing double jump exists (in second level, I managed to get up on the ledge with precise walljumping).
What else? Eh, some loose hints - when player dies, position and status of all objects in the level should DEFINITELY reset, otherwise levels where player has to figure out pattern of multiple moving obstacles get kinda confusing over time. It'd be also good if, once player dies, they'd have to press the button to restart - this gives player time to calm down from rage after dying, and pressing the button is a concious decision to continue, making player more determined - minor detail, but it works pretty well in hard games like Hotline Miami. Just a thing to consider.
All in all, not a bad game. Definitely some care and effort was put int it.