does anyone know a company that creates custom video games?

Answer 1

Quite a lot of game companies, will customised a game or make a game to your specifactions, provided you've paid them enough cash, they will make them. Similar to Movies, you need money to make the game, but in most cases you only get the money after you've finished working, except for MMO's where you can still add minor stuff whilst the game is being sold.

Custom is a weird word the game making area, and arguably all games are custom video games.

Disney Paid SquareSoft for Kingdom Hearts, Disney effectively said "Do this," "do that," "That idea is very good, put it in." A trilogy Squaresoft games that Disney inspired is the result.

Epic will Licence it's Unreal Engine out to companies who plan on using it for their game. The Level Maker comes with Most games that use the Unreal Engine. So you can create a custom level after you get the game. Plus I, myself, am in the Middle of creating a level in Unreal Tournament 04.

Then there companies that just edit games for a different market, this customization is called Localisation, which is slightly different to Translation. (You can get away with some things in Japan which you can't in the US, and visa versa)

I hope that helps.