itch.io

 Nice! Great to know you enjoyed the ground pound haha

 The transition is a bit finnicky to explain since I don't know if you use Godot, but I'll keep the explanation engine agnostic:

• First, I create a class that corresponds to the sprite that will fill the screen. In this case, it was a little star.
• This class must contain if the transition is a fade in or a fade out, as well as initial and final sizes, the fade transition, etc.
• Basically, those sprites will grow to fill the screen when the transition is a fade out, and shrink when it is a fade in.
• So, when I want to change any game scene (i.e. when the player finishes a stage), I do four things:
  • First I fill the screen with those sprites;
  • After waiting some frames, I create a copy of all those sprites, with the difference that they'll fade out this time;
  • I add those copies to the next stage;
  • And finally, I change the game to the next stage. 

 And that's it!

 In case you actually know how to use Godot, this game's source code is listed on the game page. Feel free to take a look and maybe learn a thing or two 🙂