I've used both Godot and Haxe(outside of Heaps, but there are several Haxe game engines and frameworks). Godot is better for just shipping small game projects;

I've used both Godot and Haxe(outside of Heaps, but there are several Haxe game engines and frameworks). Godot is better for just shipping small game projects; everything's in one place with an IDE that you can extend, and the design limits imposed by Godot are mostly a matter of how detailed a scene you can support. Those limits are not a barrier most indie devs are really facing - you can sink millions of dollars into a game without really needing special engine code, and because it's all open source, adding a patch for the things that do need some customization is not unfeasible. The barriers are much more likely to be in finding good tutorials, documentation, etc which Godot has accumulated plenty of, albeit not as many as Unity. Justifications for using Haxe come from a systems development viewpoint. It piggybacks on your other technology to add a layer of portability and options for repurposing code; e.g. if you want to debug and test with interpreted code but then compile it for performance, Haxe gives you several means of doing that. Easy things tend to be slightly harder just due to the nature of its cross-platform functionality, but very hard things also become possible for the same reason. Haxe the language is very good, especially considering what it's aiming to do, but it helps to have some familiarity with the technology you are targeting through Haxe first, since things like standard library functions will follow what their host environment does, which means it is not really a "write once compile everywhere" kind of deal. But if you're really set on exploring engine tech from the beginning, Haxe is a useful way to build up portability, since you can slip its output into a codebase gradually. And engines that build on Haxe are generally coming from the mindset of solving those deep technical issues, which means they often have a great pedigree but aren't the easiest to get started with(since they assume you know what you're doing and what you want out of the tech).