After a brief glance at the Xenko game engine, it looks super friendly and easy to use. I downloaded the engine and editor and spun up a third-person template project
It’s using a component-based architecture similar to Unity, but uses more of the language features of C# to their fullest, plus support for .NET libraries and utilities. One thing I haven’t tested yet is LINQ, which would be an amazing addition for online games, especially social and free-to-play setups with constant DB hookups.
The third-person demo is super concise and simple. The code is minimal: a player controller, a camera controller, and player input. It definitely needs some work to become a viable game, but the concept is undoubtedly there and it would be a great starting point for a new game.
Best of all, they announced their license terms at GDC, which are also similar to Unity with various tiers of licenses: indie, education, and more advanced tiers. Indie is free! And all tiers give access to the engine source. The advantage of higher tiers is to be announced still, as they don’t take effect until April, but one known advantage is access to editor source code.
I put the link at the top, but for convenience here it is again