Hello, it's been a while huh.
Wally and the FANTASTIC PREDATORS now has native Linux and Steam Deck support.
Oh, also Steam Auto Cloud saves (set up to be cross-platform) and even Steam Input.
These changes should allow for a smooth Steam Deck experience right out of the box, such as savedata syncing between your main machine and your Deck and also easy control rebinding.
As for now, we don't have a "Steam Deck Verified" rating, but the Linux build has been tested to work on Ubuntu 64-Bit LTS releases.
If anything, tell your Deck to run the default Linux build.
To prevent any odd-looking behavior, the Linux version will always start in fullscreen if it's in Big Picture or Deck mode by default, even if you've synced savedata with your main machine.
Thank you for playing Wally!
(a macOS port is coming in the near future!)