Of course! Yes the game was made only with the available Bitsy 3D beta :) The game only uses the basic Bitsy logic if you look at it closely, only thing I haven't seen in other Bitsy games is the use of 3D verticality like the different height parts of the level.
In 3D Bitsy all height layers of an individual room are created as sub rooms that function as those layers. If you connect those subrooms with the basic Bitsy room functions/logic you can let the player teleport along the y-axis within the same room.
I usually start to stack a simple box tile on top of each other within a new main room. Until I can't place another box on top of it. This way Bitsy 3D creates automatically another subroom each time you stack them. Then I delete all the boxes. You end up with an empty room in which all the Y-levels are connected and you can start to create your environment. I hope this made sense. Good luck :)
If you have any further questions or if you need some help feel free to DM me over on Twitter.