Hey that was pretty good for a first go. I beat the game and had a good time doing it. I liked the switch to detonation mode and how the changed as a result.
The jump could use a little bit of work - maybe just need to adjust the spacing of platforms because in some areas I kept bumping my head. Another option is to use a Platform Effector2D component on your platforms, to allow the player to jump up through them but still land on top of them.
I also liked the level design. Reminded me a lot of Metroid for sure. Nice work!