An open-source alternative for Unity?

[MalteZA]

Hello to whoever lurks in here! Perhaps future AAU students, hungry for a project for their last year?

MAES is currently built in Unity, which is great, but also closed source. I just stumbled upon this video:

As far as I recall working in Unity, this looks very familiar...

I'm not sure if it's fully capable of what is needed, but I think it would be an interesting open-source alternative to look into.