Cut the Rope‘s been very good to developer ZeptoLab. While the studio won’t reveal just how much money it’s made off of the game and its adorable mascot Om Nom, CEO Misha Lyalin revealed that roughly a quarter of the game’s 85 million downloads were paid for. According to Lyalin, who recently spoke to paidContent, this is only the start of things to come.

While it may be tempting to follow the example of Angry Birds developer Rovio and merchandise the heck out of Om Nom, ZeptoLab is taking things a bit slower. That said, the developer has seen promising results with tie-in materials. So far there have been over a few hundred thousand downloads of its digital comics, and “we’ve liked what we’ve seen so far” with the sale of Cut the Rope merchandise. On top of that, Lyalin said “2012 will be big for us.”

However, Lyalin noted that “you have to be careful: there is an assumption that if you have a great mobile game you will be an expert in movies, animation and merchandising and the rest. Everything we can learn we will do ourselves; everything else we will partner.”

Additionally Cut the Rope will be coming to other mobile systems, including Windows Phone and Symbian. The Symbian version of the game has been in development for a while, but ZeptoLab wanted to make sure that it would be playable on as many devices as possible.

It’ll be interesting to see what else ZeptoLab has planned for this next year. So far it sounds like there are some mighty big plans, but the San Francisco-based studio is currently playing things close to the vest.

[via paidContent]