Uncharted: Drake's Fortune can best be described as a mash-up of Gears of War and Prince of Persia. It combines the 3rd person cover and weapons system from Gears with the environmental puzzle platforming of PoP. Add in the fantastic visuals, music and story, and Uncharted is a lot of fun to play.
In some ways Uncharted is almost too similar to Gears. The weapons system especially is almost a verbatim copy; allowing you to carry only two firearms plus grenades (which use the exact same throwing mechanic as Gears). It also requires you to constantly switch weapons to whatever ammo type is available in the area. My main criticism of Uncharted is that it is a little unbalanced. I would have preferred more platforming and puzzle solving to gunplay. Still, while it isn't incredibly innovative, Uncharted is definitely worth playing.