In order for you to play Costume Quest 2 on Linux with minimal graphics settings, your computer must meet the following requirements
Operating System:
Ubuntu 12.04 LTS, fully updated
Processor (CPU):
1.8 GHz dual core CPU
Memory (RAM):
4 GB RAM
Graphics Card:
256 MB GeForce 8800, Radeon HD 2000, or Intel HD 4000 Graphics
Storage:
1500 MB available space