Steam Cloud has been fixed to work properly for Steam Deck and some Linux distros.
This is because it used to only download to $XDG_CONFIG_HOME/LagMakesGames/PelletDodge/SaveFiles, but some Linux machines (and the Steam Deck) save to ~/.config/unity3d/. This also fixes Cloud saves just generally not working on Linux for not being setup right ($XDG_CONFIG_HOME/LagMakesGames/PelletDodge/SaveFiles, it's supposed to be $XDG_CONFIG_HOME/unity3d/LagMakesGames/Pellet Dodge/SaveFiles).