To play Castle on PC first check if your computer can handle an Android emulator; your Windows needs 7 or later, maybe 4 GB RAM or more, virtualization, plus at least 5 GB space too, just in case. BlueStacks? Popular perhaps but Nox and LDPlayer work great, too. Pick ones that seem best for you; they help running and setting up APK files pretty well. Maybe for smaller laptops lower emulator resolution so Castle runs lag-free; just a thought it might help you.