In order for you to play Castle Story on Linux with minimal graphics settings, your computer must meet the following requirements
Operating System:
Ubuntu LTS
Processor (CPU):
Intel or AMD Dual-Core, 2.2 GHz+
Memory (RAM):
6 GB RAM
Graphics Card:
nVidia GeForce 440 512MB, Radeon HD 4450 512MB, Intel HD 3000
Storage:
1700 MB available space
In order to play Castle Story on Linux with maximum graphics settings, you need a computer with a configuration no worse than the following
Operating System:
Ubuntu LTS
Processor (CPU):
Intel or AMD Quad-Core, 2.8 GHz+
Memory (RAM):
8 GB RAM
Graphics Card:
nVidia GeForce 660 1024MB or better, AMD Radeon HD 7790 1024MB or better
Storage:
1700 MB available space