There's actually a good number of solutions to this, ranging from the extremely simple (ignore / embrace it) to the very complex. Given that the OP is a gamer, and presumably playing quite hard if he/she is wearing down the wasd keys rapidly, he/she is probably losing precious nanoseconds per keypress merely by the psychological effect of knowing that his/her keyboard is somehow "less than perfect". Thus, a solution is called for, lest he/she get called a n00b. Here's a few that pop off the top of my head.
1 - Given that the shininess is caused by a combination of chemical action and friction, modification of keypress action can reduce the friction associated with each keypress, and thus alleviate the problem. So try to press the keys with a "rolling" action rather than a "hammer" action, keeping the fingertips placed exactly on the same position on the key. This will require significant training time, this can be reduced by removing (for example) the wasd keys and replacing them with sections of cheese grater - eventually the pain and bleeding will provide enough negative reinforcement to "correct" finger posture and movement.
2 - "Rotate" your keys in order to equalise usage, in a similar way to rotating the tyres on a car.
3 - Diet change to reduce / modify the chemical composition of the sweat exuded by the fingertips.
4 - use textured tape (perhaps skateboard grip tape) on the keycaps, providing an easily replaceable textured surface.
5 - Periodically sandblast your keycaps.
6 -
http://www.cherrycorp.com/english/keyboards/industrial/keyboard_cover/index.htm7 - send your keyboard to me - obviously it's fscked, butI need the parts.