I'm a game developer, have built a profitable but small studio and I wouldn't invest a cent of my money into a game company I didn't have control over. The risks of developing a game are:
* Technical. Modern games of the retail console variety are incredibly complex pieces of technology. I would not be surprised if building an MMO was comparable to designing a car in terms of engineering effort expended. If your schedule slips, you need to rework major pieces of code just so your engine is no longer dated.
* Artistic/Creative. The game world needs to be interesting, believable and engaging. Asset production is very expensive. Let your schedule slip, and it will all feel dated.
* Gameplay. The game needs to be fun! This is much, much harder than it looks.
* Market. Distribution is incredibly hard, and even very good games often fly under the radar. Is your game the genre of the month? Is it fun enough that everyone talks about it? etc
Very rarely is someone great at all 4. I'm reasonably good at #1 & #3 and hopeless at #2, and average at #4.If you manage to somehow succeed at all four points, then you have a game that makes essentially a one time income of $x (it's spread out over a few years, but it spikes high and rapidly diminishes). Hopefully you made a profit!
And that's per game. All you need to do is mess up your next game (for instance by being too ambitious and letting your success get to your head), and you're bankrupt. The trouble is that you're essentially engineering new products each year or two. There's none of that nice, slow maturation of product and increased customer base you may get if you make, eg, bug tracking or database software, operating systems etc. Each release is potentially a very big, maybe-the-company-won't-survive flop.
There are a lot of companies that are established enough that they can survive on their fan base and income, but they're the exception, not the rule. I admire every one of them.