Edmund McMillen over at Gamasutra put together a respectable opinion post of “do-s and don’t-s”. His thoughts are inspiring, grounded, and logical. Anyone thinking about or actively working on both indie and commercial games would be wise to take heed of his suggestions. I’m a fan of his #8.

8. Stand out.
Don’t make something that looks or feels exactly like an existing work. When people experience something new they’re more forgiving of its design, and in the end your creation will get more attention. This should be obvious, but somehow goes over the heads of most designers. If you notice a trend in aesthetics or play mechanics: DON’T DO THAT. Avoid trends; innovate and break new ground. Stop making goddamn ninja and zombie games and if you’re making a shooter don’t put it in space. Seriously.