I don't know what I was supposed to do jump over the pit. I just fell into the pit each time.

Nice, very creative.

I already read the other comments so I'll avoid repeating the same feedback. But to add to those, i think the use of mouse was not necessary, I kept changing my hand from keyboard to mouse lol. When i finally realized that i could also control with wasd i was one screen away from the princess lol

Maybe a button to switch characters would be interesting and control them individually.

The puzzle is simple but fun XD
But, sadly the kids only used to grab the keys
Maybe you can add a tight space too, so only the kid can pass, and then maybe make them get separated while solving the puzzle, then reunite again in the end.  While being separated, the adult can only put something in front of him, etc, and make each of the separated way unique to their traits.
I think it will make the puzzles become more complicated and fun XD