It was released the same year the App Store launched. My wife was addicted to that game. The game and the author later disappeared. When my wife's phone was stolen in Rome, she couldn't re-download the game because it wasn't available on the App Store anymore.
Shame, too, because it was a really good game. I think it was the first app we ever paid for.
But it's likely 32 bit only and won't work anyway on anything newer than iOS 10.
Actually, there's a decent chance it won't even work in iOS 10 or would have major glitches, because legacy compatibility in iOS just isn't great in general.
And it's literally impossible to downgrade to an older OS version after Apple has closed the signing window.
This is the same that occured with PocketPC, no? I bought several games on PPC that I am no longer able to run, because lack of emulators (if any, please mention some), but mostly because many games and software at the time required an activation code which is no longer available because the companies/authors/servers disappeared.