what should i learn if i want to make a game like this?

Godot Version

4.7

Question

i am new to game development and i dont understand how it was made, like it looks 2d but it plays like 3d, the dots mouve seamlesly into the depth of the scene and the frog rotates smouthly like its a 3d model but when it colides or bounce it only move in the x and y, so how was a game like this made??

Probably just billboarded 3D sprite arranged in space. This kind of thing is often referred to as 2.5D.