Since both Astral Chain and Triangle Strategy have been mentioned, I'm gonna say Game Builder Garage.
Every "tutorial" game was super fun to create thanks to how intuitive and how much personality the whole thing oozes. I also spent tons of hours doing my own little games. Not always amounted to something, but It was fun nonetheless.
I hope they give it another try on the Switch 2 with more optiona and specially a higher object limit. It was the main thing that was holding it back from being the best affordable and easy to use "game engine".