

Just worked for me. I experienced no issues with saves, and the opening cinematic had no issues without any tinkering.

Swapped a and b

Swap A and B around, the default controller scheme has B as select and A to cancel
Swapped A and B
Saves are not synched through steam cloud.
Not being able to save is a huge red flag. Multiple updates have been released but no fix for steam deck saving
Added radial menu on left trackpad for hotkeys
Low graphics settings
Saving does not work and developer response on the steam forums make it clear it is not a priority to fix it.
Developer stated in the steam forums they have no plan to fix saving on the steam deck so playing it without being able to save your progress is a waste of time.

The launch command fixes the only graphic glitch (a cut scene near start of game) and the 7.0rc3-GE-1 version is needed for saves to work.
WINE_DO_NOT_CREATE_DXGI_DEVICE_MANAGER=1 %command%
Nicely calm game. Good for chilling.

Using ProtonUp to switch to ProtonGE7.0rc3-GE-1 for this title will allow for a smooth experience
SteamDeck players are likely to experience wipes of these changes on updates to SteamOS, but I have no way to corroborate this theory. ProtonUp is not necessary, but is available in CLI and GUI, the alternative being downloading and configuring yourself. Happy farming!

Unless a solution is found, you cannot save progress through proton. This is not a game that you want to play from 0 every time.
WINE_DO_NOT_CREATE_DXGI_DEVICE_MANAGER=1 %command%
Save game returns "Save failed", yet to find a possible solution using protontricks/fixes etc
Cutscenes bugged originally, the command I launched with fixed it.
Everything else is seemingly working perfect. Shame too, pretty cute looking game. The demo saves properly, so it seemingly was working in the ~0.2 version range the demo is based on, but running on version 0.4.4 does not save player progress. This is likely to do with the findings listed in this forum posting; https://steamcommunity.com/app/1201230/discussions/0/5019836142104211831/
Doesn't save and the fewest people would be willing to beat the entire game in one sitting.
The movie scenes was scuffed with weird coloration artifacting and impossible to make out
The game would say "Failed" every time it tried to save. And didn't notice any way to save manually.
The initial control setup works perfectly for the game with the steamdeck.
You won't initially notice anything is off before it plays the cutscene which is completely intelligible, however the big problem comes immediately after when it tries to save .... it can't Meaning you will be playing the entire game without being able to save.
So unless you're a power gamer who can beat this in one sitting, the game is not "playable" in its current state.
Game saves periodically but all report "save failed."
Cutscenes were displayed in the wrong colors with odd transparency.

Immortal Life Patch on 5.12.2022 broke the game launch for All proton versions I tried.
If you want to give it a go again after their next patch, be ready to get an immediate refund if it still fails to launch. Don't even bother unless they've released a major update after May 13 2022.