Ask HN:investing in mobile game development

I am considering funding development of two smartphone games. Games would be developed by 5 person development studio. We are based in Europe. The idea is that studio could use extra funding to build portfolio and make more money and obviously I could make some money of it as well. The deal we plan is my investment of X% of development budget and getting Y% of return in game sales where X is close/equal to Y. Game concept looks good ( yes I know is extremely vague description, game is in sports category )

About me: I have developer's background but I don't code for living for ~10 years. I am able to verify game studio experience and skill set but I am not a gamer at all (mobile nor console). Last time I spent serious time playing games was in Commodore 64 heydays... I consider my lack of mobile gaming experience biggest drawback.

About game studio: limited portfolio of mobile games - 5 titles, only one quite successful in number of countries ( ~4 times return on 1 man-year development budget). They have pretty good understanding of technology and some design talent. Significant experience on PS console an older devices like Gameboy. They have every good, well known publisher.

Obviously the biggest risk is if the games are going to catch on and get sales. Even more obvious - coming up with good game concept is the hardest part and mobile game market is crowded

Did any anyone try this kind of investment approach from investor or hacker perspective? Would you take a shot at estimating risk and expected value of return? Thanks