Hacking Into NES Games

When i was cleaning my room up, i managed to stumbled upon one accessory i kinda wished i never owned... but regardless, i do still have it after all these years, seeing that there was some games i could not beat legitimately, like the first TMNT, for instance.

Anyway, the Game Genie came out on NES, Super NES, Sega Genesis and maybe some other consoles i'm not sure which other ones it came out. And you might say that this was a precursor to the Action Replay thingy that came out on Gamecube, Playstation, XBox and such years later.

Note: Game Genie was released by Camerica, although the company itself went out of business afterwards.