This week has to be Christmas for people who developed an engine not named Unity.
The only open source project that remotely resembles Unity is Godot.
It was not completely open source, but it is now (if I didn't read it wrong).
For those who missed it like me, Unity raised prices: https://news.ycombinator.com/item?id=37481344
https://blog.unity.com/news/plan-pricing-and-packaging-updat...
Looking at https://steamdb.info/tech/Engine/Love2D/, there's only two games on that list that (based on steamspy numbers) that would actually be affected by the recent pricing changes.
If you're objecting to Unity on moral grounds for it's new DRM philosophies, or it's CEO, well those were just as valid almost 10 years ago.