Yet another casual online game company is coming out of hiding today as Mytopia announces its platform for simple online games such as poker and puzzle games.

But the Palo Alto, Calif., company hopes to set itself apart because it allows players to compete with each other across platforms. Hence, a Facebook gamer could take on a MySpace player in poker.

Typically, game companies target one platform, such as the PC, and optimize a game for it. Then they translate that game, a process known as porting, to another platform. That often involves changing the art work and controls to suit the particular platform. But Guy Ben-Artzi, CEO of Mytopia, says his company has tools to make cross-platform gaming easier.

“We are trying to end social network segregation in games,” said Ben-Artzi, who started the company with his sister, Galia Ben-Artzi, last year.

Guy Ben-Artzi admits this isn’t easy. Some platforms such as Google’s Open Social Platform aren’t even finished yet. It’s hard to design games around platforms that are still evolving.

He also said the company is now starting its own Mytopia casual online gaming world, where players can compete against each other, check their status on leaderboards, and otherwise socialize with others online.

The world will start with eight simple games, an e-commerce store, an inventory system for gamers to store their wares, and chat forums. The limited launch will help the company iron out any scalability issues, he said. Six more games are in the works.

Making yet another casual game platform stand out will be tough. Big portals such as Yahoo!, MSN, and Electronic Arts’ Pogo.com already have millions of players playing the same kind of simple games that Mytopia will have. The portal games appeal to older gamers, including women, who don’t have a lot of time to play. That’s a contrast to the mostly male hardcore gamers aged 18 to 34 who don’t mind playing 20-hour games.

But Mytopia is also going to target the younger fans of such social networks as Facebook, Bebo, and MySpace. It is also going to be available on networks including Okut, hi5, Yahoo! Widgets, iGoogle Gadgets, Apple Dashboard Widgets, and Microsoft Vista Toolbar Widgets, and, of course, Mytopia.com.

Mytopia’s games are based on Adobe’s Flash player and run in a browser. Later features will include rewards for achievements such as beating someone in less than 15 minutes in a chess match. Galia Ben-Artzi, co-founder and director of marketing, gave me a demo of the world at the Game Developers Conference. Mytopia has a cute art sytle, with titles such as Video Poker, Sudoku, Spaces and Hearts. She showed off the world’s cross-platform capability in a poker game.

The variety of platforms they’re supporting is impressive for a small company. I expect a lot of companies would like to license this technology, if it works as Guy Ben-Artzi says. But he says the company wants to own the community of gamers that it creates. The platform tools will help people manage multiple identities across social networks.

I’m coming across a couple of new casual games companies a week. All of them are inspired by the success of sites such as Pogo.com, which has 1.5 million paying subscribers for the premium version of its site. They’re also impressed at how Nintendo has been able to broaden the video game market beyond hardcore gamers with its Wii console. And then there are companies inspired by the more frothy excitement around Facebook applications and widgets on social networks. The Casual Games Association estimated the market for casual games reached $2.25 billion in sales in 2007. (our coverage)

“We can’t go on seeing two game companies coming out every week,” said Thomas Cole, a partner at Trinity Ventures, which has funded four game companies, including casual game company Fluid Entertainment.

Guy Ben-Artzi said