This game is clearly meant to be a Mario replica, and whilst there's nothing inherently wrong with that, I just find that this game does what Mario does, but just worse. The movement is very floaty which isn't really a good thing for platformers, and the enemies offer no real threat to you. The mines just aren't very useful considering how slow enemies are, also I can just jump on the enemies instead which takes much less time, and there's no real need to kill the enemies in the first place since I can just run past them with ease. Overall I can tell that you put at least some effort in this game, and I hope you'll get better at making games over time, everyone starts somewhere.

Edit: Some suggestions, for one it would be nice if as soon as you stopped pressing left/right you stopped moving completely instead of continuing to glide for a bit, also considering the similarities between this and Mario, if the mine powerup worked a bit more like the fireball that would be much more useful, as in instead of just planting it down somewhere and waiting for an enemy to walk into it, you could throw it at the enemies and it would blow up as soon as it lands somewhere.