First of all, I have 2 suggestions:
1. have a separate key (perhaps e or f) to interact with objects so you can still drop down when you're in front of a chest or a portal
2. Have a hold button to jump system so that when you have the extended jump ability you don't accidentally jump into a mine or an enemy.
And also here's some info about the blade boomerang; it disappears if you throw it outside of the stage so you loose a clip (@Holux), and if you throw the boomerang, run backwards and the throw it again and keep spamming the attack key you can get an extra boomerang on the screen. I managed to get 4 boomerangs on the screen at once by doing this, which made it a really powerful weapon.
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