I already posted this on discord but I'll paste it here too for visibility.
I just played it and I actually really liked it. the platforming is solid the sounds are nice and the gameplay mechanic of jumping on the the vaccine cells is really fun imo. if the game was like three times the length it is now im sure i would have played through it all. pretty fun in the beginning cutscene when grandpa says "the vaccines give us knowledge cells the ability to fight virus cells" or something like that the last word "cells" gets cut off and goes off screen. also on the fourth level i found i could really easily complete it without having to step on two out of four of the vaccine cells at all. other than that stuff i liked it a lot tho. characters are also really cute. good job! :)