The RPG Maker 2003 engine, on which the game is made, does not support Linux. But there is an excellent working, unofficial, multi-platform EasyRPG Player. Download it and unpack it in the game folder.
Left-bottom sprite (first frame of idle right) in "Basic Charakter Spritesheet.png" should be shifted right by 1px. In its current form, idle right loop doesn't look like the reflected idle left loop.
🤦♀️ I found saves in this location, on two different devices (Android 10 and 11). If you can't find them on your device, it's your problem. Read previous comment and use your brain.
