I also have my own game engine, if you’re happy with 2D retro pixelart graphics (polygon support and 3D comes after I move some of the rendering away from the CPU to the GPU). It also has software synths, if you want adaptive soundtracks.
I did my part with this post - https://programming.dev/post/2947073
My list has a few things that aren’t listed in that GFS link, which might be useful for the more specific indie types (Solarus, OHR, OpenMW)
Stride does look like a very good alternative if the intent is a 3D game and C# programming, so possibly the best case for Unity veterans in that regard.
What are the downsides for using Unreal?
As terrible as Unity’s API design is, Unreal’s API design is 10x worse and still feels stuck in the 90’s.
It is a performance hog. Unity can run on relatively low spec hardware.
Gamemaker, my old friend! 🫂
