Tigervision is another obscure third party company. There are a total of 10 games made by Tigervision, including the most common, King Kong. King Kong is based on the Universal Studios character, but the game is rather boring and similar, but not as good as Donkey Kong. The other games are somewhat rarer, Miner 2049er II and River Patrol being among the rarest. I've seen Espial start climbing in value, especially boxed versions. You can expect to acquire half the games with relative ease, and the other half by opening up your wallet a bit. There are cartridges of titles that have different color molds. I don't know how legitimate these are, so I'm not listing them at this time.