I have a pretty sweet idea for a game.
It's like a cross between Zelda, Gears of War, Tomb Raider, Deus Ex, and Uncharted. These games are completely unrelated, I know. But hear me out.
You play a team of treasure hunters. It's set on an alternate Earth, where humans share the planet with many other intelligent species. All the races have different and unique Homelands. Humans lack the ability to use Magic, unlike many other Races.
The story would be upbeat and cheerful, and the enemies and villains would be purposely over-the-top and creative (evil unicorns, anyone?). The main characters would be funny and likeable, and human. The protaganist would probably not be white, to avoid the whole "white man with short brown hair" trend that's going on.
The levels would be kinda like Zelda's dungeons, with Uncharted gameplay and RPG elements. The dungeons would have more than one way to solve them, and suit many different playstyles. Humans aren't born with any magical abilities, but they can use magical artifacts found in dungeons. The artifacts can range from upgrades (like decreasing fall damage, or increasing accuracy), to completely new abilities (like telepathy or fireballs). Most artifacts are optional to get, but some will be required to advance. The dungeons will involve platforming like in Uncharted, and you hold the left trigger or right mouse button to take out your weapon and aim.
You can't carry every artifact or gun you find, the inventory system would be like the one in Deus Ex. You can periodically buy size upgrades to your inventory, like in Resident Evil 4.
It wouldn't necessarily be a graphical powerhouse, but it would have nice-looking graphics, and excellent art direction. A lot of work would be put into the atmosphere of each dungeon.
So there you have it.