There is no "regular developer". Developers always need to apply ( and probably learn in advance ) more than just programming skills. If you write simulation software, you need skills in this field ( physics, chemistry, biology... ), if you write banking or business software you need experience in this area ( in case of banks more than you might want to know... it just makes you fear for your money to see how banks handle computers and data ) and if you write software for another market you need other special skills. If you aren't working for some niche market 2-men software company, you will always be part of a team and handle only a part of the aplication. When developing a game for example, you might end up writing and optimizing the net code. As with all teams, you might never even have more than a general understanding what other members of the team do, because they have other, very specialized skills.
While some games call for heavy optimization, almost all non-UI applications need optimization, too. Batch processing is crucial in large companies and the difference between 100.000 records per hour and 200.000 records per hour is double winnings. And you bet the boss wants this optimized to 300.000.
All developers need additional skills. Those needed for writing games sound like more fun, but that's a personal decision what might be fun and what not. It's not harder to master than any other secondary skills. It is a bit harder to get in the market, because the need for game developers is smaller.
