if you are making opcode asm modifications that may be how you are being detected, try hardware breakpointing to find addies enstead of inline asm hooking if that is what you are doing. Idk anything about the game you stated, but I do know a little bit about avoiding detection.
detections also like to use byte pattern recognition.
they like to scan for common strings in 'hacks' 'tools' 'cheats' etc
they like to check the debug flags and call isdebuggerpresent();
they like to make hooks(local and kernel sometimes SDT or vtables even)
they like to crc the client
they also like to watch for certain api calls
I once coded a hackme which I hooked (on a userland level) all applications. I hooked the writeprocess memory api address in them all, and made it go through a local routine so i could detect anything trying to write to my hackme(and force terminate the hackme). I was able to workaround this by making an NtWriteVirtualMemory callgate. so these are just some detection examples.