I'm expecting cut backs with Vita versions, but some games handle it better than others. I mean, all the games I listed will be fine for me and I'll be buying them all on Vita regardless, but for example Attack on Titan - the texture pop-in is absolutely insane, I'm sure they could've done something different with that. Same with Yoru - it seems playable, but it's taken a massive graphical hit AND it's unstable. Either keep the graphics toned down and get it running smoothly or tone up the graphics and just take the hit on the gameplay, not the weird hybrid in between that they seemed to go for.
If you are talking about framerate,Yoru ni Kai Kuni is not unstable. I played for about 10 hours, and besides some drops here and there, Yoru runs perfectly fine. And complaining about pop-in in musou games?
(edit: Nvm, I just checked a gameplay video online and yep, the Unity logo was there. Whyyyyy? And why does this engine continually run so poorly on Vita?)
Still, most of Bamco's cheaper licenced stuff runs like crap. I just finished Mahouka (enjoyed it by the way) and it was littered with slowdown throughout. From what I've seen of World Trigger, it looks fine.
Not every Unity game runs terribly. The latest Unity games that I played runs OK (Nobunaga 201X and Gundam Conquest). But it is an engine that isn't fitted to run vita games. Most of unity games runs with unlocked framerates (so it actually spend 5% of the time in 60FPS and 95% in 30FPS or less, and fluctuate wildly, even when nothing is happening on screen) and have long loading times (on every system, like PS4 and IOS). It just don't play well with the vita strengths.