Really cool little game, unfortunately I couldn't seem to get all three of them jumping + moving at the same time working with my crappy cheap keyboard, too many inputs at once ig. Would have loved to finish it!
Actually, I've created mouse controls for people specifically with your issue. It took me a full day to implement without bugs because I can only get discrete mouse position data lol, and I guess I didn't really put much of it in the tutorial because of time constraints, but it's there.
Basically, to get them to jump with the mouse, you click down, and when the mouse passes the column with the cube in it, the cube jumps. So, you can click down and quickly swipe across the frame and if it detects that the mouse was on one side of the cubes on one frame and the other side of the cubes on the next, it makes sure all the cubes jump. There's a bit more to it than that but that's basically the gist of it and the rest should be rather intuitive.
ok now ive added a ton of stuff to the page and description to make sure people know about the mouse controls even though the game only kind of mentions it in really small text in parentheses in the tutorial (because i didnt have time left to draw a cursor and parent it to that hand icon. i basically finished basic cycle of the final boss right before the deadline) lol