A little developer note: The game in its current state is not completeable as intended due to lack of time for playtesting. However there is one "mechanic/exploit" you can use to reach the finish...
Here is an overview of all the controls:
Left/Right arrow keys or A/D - Walk left/right
Up arrow key/space - jump (space is also used to change the current intro slide)
E key near a mushroom panel - Put electroshroom in/out of the elevator to make it move forward/back
Pause menu is there, but the buttons did not get implemented correctly, so they do nothing. To exit the game before finish, press Alt+F4 (very intuitive game mechanic if you ask me).
Dont forget to remove the mushroom before exiting the elevator.
PS: When you reach two elevators that are just way too high to reach normally, press Space + Up arrow key at the same time to perform an unintentional "Super jump" that gives you tripple the amount of height. That way the level can be completed.