> main trouble to me has been caused by unity games

Generally it's probably just bad optimization. But that only gets you so far because Unity's asset streaming is designed to work with level-based games. It will only let you unload assets if you package them per-level and then swap them in and out at load screens between levels. Absolutely useless for games like KSP.

> Absolutely useless for games like KSP.

and yet KSP flies fine, while visual novels crash