Nice Game ! i like it, here is some notes:
1- try to make the dialogue box controllable, like when i want to skip a certain dialogue or keep reading for a longer time , dont make it controllable by a timer
2- try to teach the player how to play with game design and without saying too much (just a suggestion :D )
3- jumping feels a little bit too fast , because of the high gravity, try to raise the gravity only when the player is falling, that way the jump doesnt feel floaty or fast
4- spamming a lot of enemy in one area and make their health larger is a really poor design and not the right way to raise the difficulty or make a fun game
5- playing with the tank should make me feel powerful , but it doesnt. the tank is way too slow , it has the same health as the player, and the rocket damage is not that much
6- also following the cursor is a lit bit broken, some time the character(hero) follow the opposite direction of the cursor
i hope i see more of your game soon , cant wait to play more of it, stay awesome :D