Hi @qualitaly91 and thanks for your query. Indeed, the Tobii 4C Eye Tracker (and all our consumer level eye trackers) is designed to operate in tandem with the traditional keyboard and mouse as the primary focus is on augmentation with games and windows interaction, not as a complete interaction replacement as can be the case with the Tobii Dynavox range of eye trackers.
Accordingly, any software solution that offers complete hands-free gaming with the 4C will be created by third-party developers. Fortunately, there are a number of options available to you in this respect. The first is Xcessity for which you can learn more @ http://iris.xcessity.at/ & https://www.youtube.com/watch?v=yz9oUuNEnz0 Hopefully, this will provide you exactly what you are looking for!
With regard to the capability of the I-12 to run games, I would refer to you contact Tobii Dynavox Support @ https://www.tobiidynavox.com/about/contact/contact-tobii-dynavox-intl/ and they should be able to give you a better idea of the I-12 capabilities in this regard.
Please let us know if we can be of any further assistance.