Which 2d game engine to choose to immerse the artist in the topic?

Question

Game development

The point is this. My wife draws, loves to draw, wants to try to apply it somewhere. One of the options is to try yourself in the game industry.
I see this for myself, so after work I prepare for her some kind of field of activity with the character, having previously tried something myself, I give a brief introduction about sprites, some tools, etc. and she begins to dive into the topic, at times using my feasible help.
What is the difficulty and the question is - what is the best game engine to choose for such training purposes? Priority - the minimum entry threshold and ease of deployment, bells and whistles, chips and other perspectives are not needed, there is no task to get into the top super games, the task is just to touch all this and get an idea. So that the red rectangle starts to run and you can draw everything else, figuring out how best to apply light and shadow, animation, etc. there.
I myself am engaged in a web backend and therefore with everything that runs, jumps, jumps and blinks a sign very weakly.

Answer 1

Then Unity . A running red rectangle can be made with a few lines of code. Collecting the game is also easy. The easiest, perhaps.