In order for you to play Moonstone Island on Linux with minimal graphics settings, your computer must meet the following requirements
Operating System:
Linux (Ubuntu 20.04)
Processor (CPU):
Intel Core i5-2300 / AMD Ryzen 3 1200
Memory (RAM):
8 GB RAM
Graphics Card:
GeForce GTX 460 / Radeon HD 5850
In order to play Moonstone Island on Linux with maximum graphics settings, you need a computer with a configuration no worse than the following
Operating System:
Linux (Ubuntu 22.04)
Processor (CPU):
Intel Core i5-8400 / AMD Ryzen 7 2700X
Memory (RAM):
8 GB RAM
Graphics Card:
GeForce GTX 1050 Ti / Radeon R9 280X