How do I love games and hate games businesses, let me count the ways. User expectations are pegged by AAA games, whose budgets you cannot possibly match. Those AAA products set a price point at $DIRT_CHEAP. (Angry Birds costs what?) Your core users are thieves. When you fail at marketing on day one, which you will because everyone does, in any normal business you get progressively better but in games the obsessive fetishization of the new means your game is virtually sunk. It is virtually impossible to iterate based on user feedback because your users are a) transients and b) not wonderful people to deal with. Gamers are virtually immune to ads, don't search for anything gaming-related, don't pay prices sufficient to justify CPc spends, and if by some miracle they hear sbout you via word of mouth they will search for you on PirateBay/etc first and Google second. Meanwhile, in addition to megacorps staffed by people who have been doing this professionally for years, you are also competing with a virtually inexhaustible supply of hobbyists, because perhaps 3 out of every 4 CS majors got into computers to make video games and the fourth one is lying.
Does any of this get better for mobile devs? No, it gets worse, unless you're picked by the platform's kingmakers.