In order for you to play Lost Castle on macOS with minimal graphics settings, your computer must meet the following requirements
Operating System:
OS X 10.6.6 or later
Processor (CPU):
1.6 Ghz
Memory (RAM):
2 GB RAM
Graphics Card:
GeForce 8800 or Radeon® HD4800 series, 512 MB of memory
Storage:
2 GB available space
Sound Card:
Any