HyperPin is a frontend, it is not a game or an emulator. A frontend is a menu system that can launch other programs and emulators from one menu. Without a frontend you would have to individually launch each program in Windows. If you're using an emulator you would also have to find and launch the games you want to play. HyperPin simplifies that process by using a system of menus to launch your games.
There are several other advantages to using a frontend. HyperPin uses real arcade controls, rather than a keyboard and mouse, to provide simple menu navigation in your arcade cabinet. HyperPin also hides your normal Windows desktop, providing a more authentic arcade experience. Since it uses simple controls and can launch a variety of programs, HyperPin can turn your pinball cabinet into a fully functional multi-game machine. Your friends and neighbors never have to know that you have a regular home computer hidden in your arcade cabinet.
Since HyperPin is primarily designed for emulator launching it is important that you already have some emulators installed on your computer. It's also important that you have games ready to play. The main focus of HyperPin is the pinballx emulator, but you can find many emulators for other arcade and home console systems. Some knowledge of emulator usage makes setting up HyperPin easier, but it's not completely necessary.