Good starting point for a Platformer. Played it on mobile, performance was great. I like the sprites used for the player character and the tilemap. Enemies and UI are obviously still placeholders, but I'd suggest making sure the resolution of all your assets in the final game are consistent. Certain elements currently are higher/lower res than each other, makes the game lack visual cohesion.
Only other real suggestion is perhaps making the tap targets for the touch controls slightly larger than the input graphics themselves. I'm on a Pixel 3a, and I found myself missing the buttons rather frequently. Since you aren't looking at the buttons directly and can't find them by feel like a normal controller, having some give there tends to be helpful.
Also, hell yeah for fellow Construct user 👍