This is a very simple engine, I will probably change it into a platformer later. Arrow keys to move, spacebar to throw a fireball, and use the color slider to change the color of your fireball. Some of my favorites are 0, 125, and 90, all with a range of 20. Note: I would recommend sticking to the lower end of the "color range" because at 100, the flame's colors aren't very distinct.
Thanks to Turtle1331 and their project Mouse Trails 100% Pen for supplying the original system for the flames. This project was originally a remix, but as I kept making the system, I changed a lot and added as much as it had already, so I copied it into a seperate project.