When talking about game designers, a couple of (cliché) names spring to mind for me. The first being the much fabled Shigeru Miyamoto. The second being Peter Molyneux, who oddly enough was made an OBE in 2004.
Both these guys have been credited with 'pushing game play to a new level'. A somewhat odd phrase that will mean nothing without some form of explanation. As far as I myself understand it, game play can simply be defined as how the user interacts with the game. Do they for example take control of one single character and navigate it through a set story? Or do they play as a kind of overseer or god, controlling the action of many individual characters? It is obviously a lot more complex than that and a games designer is responsible for finding new innovative ways to interact.
Some take this a lot further than others mind you and there are also some tried and tested formulas.
One particular formula that has stood the test of time very well is the FPS aka first person shooter. The mechanics have remained much the same since the day of Doom. Sure they look more attractive, have lots more flashing lights and neat little gimmicks, but they barely mask the fact you’re walking from room to room shooting back at whatever has the audacity to shoot at you.
Then again if it ain't broke don't fix it.
'Game play' elements I often enjoy in games often (get rid of one) revolve around personalization. I find it a lot easier to invest a large amount of time in a character or setting I can relate to or have some kind of vested interest in. I often see games such as ‘Gears of War’ like Hollywood blockbusters, good to just sit back and enjoy, but you leave having gained very little.