Great job, especially if this is your first game.
I would like to see coyote-time being implemented as it improves the "game feel" part of any platformer significantly.
I think there's potential in the tincture mechanic, keep up the good work!
Viewing post in Lazlo's Tinctures (Jackie's Game Jam Edition) jam comments
Yea thankfully coyote time is not that difficult to implement.
I like to store the last grounded time, and then allow jumping if current time is withing the coyote time threshold of the last grounded time.
You could also implement reverse coyote time, where you allow enqueueing jumping in the air, and then it automatically triggers when you hit the ground, this is the fundemental part that makes platformers feel very responsive.