The best game engine for beginners depends on one question

If you want to learn programming, a beginner engine is a classroom. Scratch, GameMaker and Godot all teach you to think like a programmer, at different depths.

If you want to make a game without learning to code, you need a tool where logic is visual or written for you. GDevelop's events and AI game makers are in that half.

Neither half is better. Many people start in one and move to the other.

Scratch, from MIT Media Lab in 2007 and now the Scratch Foundation, is free for everyone and uses blocks you snap together. It is built for young learners, and adults learn from it too.

Its games live on Scratch's site. It is a wonderful place to learn and not a place to sell a game.

GDevelop is open source and uses a no-code event system. It exports to the web, Android, iOS and desktop, and has AI assistance built in, with more AI use on paid plans.

It suits people who want visual logic and a path to publishing, without writing code.

GameMaker is a 2D engine. It is free for non-commercial use; selling a game needs the Professional licence, a one-time $99.99 according to its site.

Its language, GML, is designed to be approachable, and many well-known indie games were made with it.

Godot is free and open source under the MIT licence, with no royalties, and does 2D and 3D. Unity Personal is free for individuals and small organisations under $200K of revenue and funds raised in the last 12 months.

Both expect you to learn to code eventually: GDScript or C# in Godot, C# in Unity. They have no ceiling, and they have the steepest start.

Flockbay is a free desktop app for Windows or Mac with Godot inside. You describe the game, the AI asks questions and writes a brief, and after you approve it writes the GDScript into your project.

It is for people who want a full engine's result without learning to program. You still design the game and judge it by playing, which no tool does for you.