yeah the game can be surprisingly demanding at times
Viewing post in "Voices Of The Void" Pre-Alpha comments
That's the problem with ever advancing game engines. It doesn't matter how stylized or "retro" looking your game is if you're developing it on something like Unreal Engine 5, which has higher requirements.
I can understand why the developer didn't actually use the Source Engine though. I'm pretty sure this game's inherent design (the big map) would be difficult to do on Source.