In order for you to play Psychonauts on macOS with minimal graphics settings, your computer must meet the following requirements
Operating System:
Snow Leopard 10.6.8, or later.
Processor (CPU):
Intel Core Duo Processor
Memory (RAM):
2 GB of RAM
Graphics Card:
ATI X1600 / NVIDIA 8600GT / Intel HD3000 or better card with at least 128 MB VRAM
Hard Drive:
4GB minimum hard drive space
Controls:
Keyboard and Mouse
Leopard is not supported
In order to play Psychonauts on macOS with maximum graphics settings, you need a computer with a configuration no worse than the following
Operating System:
Snow Leopard 10.6.8, or later.
Processor (CPU):
Intel Core i Series Processor
Memory (RAM):
4 GB RAM
Graphics Card:
ATI HD 3870 / Nvidia 8800GT or better with at least 512 MB VRAM
Hard Drive:
4GB minimum hard drive space
Controls:
Game Pad (optional)
Leopard is not supported