I thought this game was really fun, I certainly was challenged enough to want to make it to the end. Well done on getting this done in only a week.
The falling mechanic is a good choice. It allows the player the chance to speed run (which is usually the goal for some players) but with the added challenge of risking a death because of it. The only difference with your game compared to something like Going Up is what happens after falling. Going Up keeps the player alive the whole time, while yours essentially kills them then restarts the level.
This might be ridiculously complicated to implement for such a simple game but maybe falling to a certain speed causes a portal to open up beneath the player and teleports them back to the beginning. This way, the player doesn't get a jarring experience that involves menu screens to restart.
Simpler mechanics to implement might be the ability to do a mid-air jump if the player hasn't already jumped. I just found that a couple of times I would try to jump but would fail even though it seemed like I was still touching the ground.
Also, locking the mouse position and hiding the mouse would improve gameplay. It is a little distracting seeing the mouse go all over the screen and it actually prevents the player from looking around if it goes onto another monitor (that's what I found anyway).
None of these issues were game breaking in any way just a little inconvenient. Overall, still really fun to play.