I looked like I somehow beat the 3rd level despite one of the dogs falling.

When making platformers, I would advise against putting the next platform the player needs to reach outside the player's view unless you have some visual indication of where it is. For example, Mario uses coins to indicate far away platforms and Sonic uses rings. This makes it so the player doesn't have to guess where they need to go to not die.

Very difficult I got to 3 dogs and couldn't keep track of all of them. The control's feel a bit loose.