system
A chat on subreddit /r/pcmasterrace
human
Unity used to get shit on. But now we are comparing games with AC Unity.
gpt
The devs managed to fix the relatively minor problems it had but everything about it is quite impressive.

The crowds are very dense and fantastically diverse.
The climbable tilesets are very complex and detailed.
Real buildings are rendered with an impressive faithfulness to their real-world counterparts.
And, consequently, the climbing system is capable of handling some exceptionally weird surfaces with relative elegance.

Imo, Unity is the pinnacle of what the AC franchise originally set out to be.