[14] To give the game a sense of depth, the graphics engine makes heavy use of particle systems, fluid simulations for smoke and water, normal mapping, and dynamic lighting, all rendered in different layers.

Basso deliberately did not leave text or strings in the code, with animation files and other assets identified using numbers alone.

The game includes collectable items stored in unreachable areas, that lock the player out of further progression if picked up.

His effort was successful, as the game's harder secrets were found via normal methods first, in the first month after launch.

[16][17] Basso believed that some puzzles would take 10 years to solve and so constructed the game to be as widely compatible as possible, in the hope that future computers would still be able to easily run it.

[26] Christian Donlan from Eurogamer lauded the game's immersive exploration, calling it "an astonishingly rich Metroidvania".

[30] Shaun Prescott from PC Gamer also gave it a 90, calling it "a sleep-destroying puzzle metroidvania of baffling depth".

[35] Rebekah Valentine from IGN awarded Animal Well a 9/10, describing it as "a beautiful, multi-layered puzzle box that's both fun to simply play around with, and an utter delight to slowly crack open".

While the PlayStation 5 version is over 100 MB, most of that size can be attributed to a single high resolution image used in the console's UI.