Not easily, but if you become a game developer you can start to tell at a glance. Unity games have a very specific type of jank and look + feel. (So do Unreal, Source, and Godot games.)

Even if a game is highly stylized, a Unity game always "feels" like a Unity game. Kerbal Space Program, Pokemon Brilliant Diamond/Shining Pearl, Pokemon Go, Cuphead, Untitled Goose Game, Cities Skylines, Valheim, etc. It's a combination of physics, shaders, and input latency that's hard to put into words.

The closest I've come to seeing a game that breaks out of the "made in Unity" feel is Stanley Parable Ultra Deluxe, which was made in Unity but pretends to be made in Source (the original Stanley Parable was made in Source).