Interesting story. I like the mechanic of having to switch between worlds. The platforming is quite solid and nicely built around speed running. The character portraits are quite nice. I do have to say using acceleration in the character movement leads to some wonky movement sometimes, though when you do have speed it goes quite smoothly. Maybe allow the speed to build up faster? The dash had a nice animation and the sections where you had to air dash continuously upwards were challenging.
Keep up the good work!