What is this aesthetic called?
The main elements are surrealism, technology, alien planets, space, pre-rendered 3D backgrounds, point-and-click adventures, and hidden subplots.
Media includes Trace (a game on CoolMathGames), Drowned God (shown here), The Neverhood, Myst, GARAGE: Bad Dream Adventure, and Sanatorium.
Some games that partially have this aesthetic are Fran Bow, Samarost, Machinarium, Hylics, and some parts of Psychonauts (specifically the Milkman Conspiracy and Sasha's Shooting Gallery)
On the topic of Sasha Nein, some characters that fit this are him, Wayne from Hylics, Ulysses from ENA, and Motherboard from Cyberchase (her design, mostly)