Honestly the main issue would be on our part due to lack of time, the first part that the player is supposed to go to is the left side where you unlock the dash, having access to a coin-like collectible in order to guide the player would certainly help out with it, but we just simply didn't have the time to implement it. Once you get the dash, you can go through the 2nd section where you had trouble with easily.
The key is also used only to progress after the area on the top right as well before the boss battle, so I find it funny how one can literally just... completely skip the dash and head straight into the boss fight.
Thanks for playing though!