Yes but a non trivial amount of the app would need to be obfuscated. You wouldn't be able to just obfuscate the license validation code as the caller could then

Yes but a non trivial amount of the app would need to be obfuscated. You wouldn't be able to just obfuscate the license validation code as the caller could then be modified to skip over that function call. If this really is as slow as it sounds like it is (still interesting though!) then it wouldn't be practical for game programming. The entire game would run like molasses.