A genre defining game is when what makes a certain genre good or appealing is at its most prominent. When a game you play makes you think to yourself "This is why I play -genre-!", it's probably a genre defining game for you.
Readers of the Escapist may have seen the most recent episodes of Extra Credits where they talk about how awesome Journey is and how it parallels the hero's journey. One could take this to interpret Journey as a genre defining game for the Adventure genre.
A personal example:
EVE Online defines the MMO genre. It's a game where it takes the initial appeal of MMOs (Which is a thriving world run by players) and puts it front and center. Where other MMOs will say "No, you can't grief or scam players", EVE will say "Hm, that's a good idea!" Players can do almost anything they want, as long as it isn't harassment, death threats, hacking, etc. CCP doesn't put a limit on what you're allowed to do in the game. Players can form a company, acquire real estate, war over said real estate, have a booming trade, build massive empires and so on and so forth. It's all awesome. That's why EVE defines MMOs for me.
What games would you say defines genres? You can disagree with me if you want.
Readers of the Escapist may have seen the most recent episodes of Extra Credits where they talk about how awesome Journey is and how it parallels the hero's journey. One could take this to interpret Journey as a genre defining game for the Adventure genre.
A personal example:
EVE Online defines the MMO genre. It's a game where it takes the initial appeal of MMOs (Which is a thriving world run by players) and puts it front and center. Where other MMOs will say "No, you can't grief or scam players", EVE will say "Hm, that's a good idea!" Players can do almost anything they want, as long as it isn't harassment, death threats, hacking, etc. CCP doesn't put a limit on what you're allowed to do in the game. Players can form a company, acquire real estate, war over said real estate, have a booming trade, build massive empires and so on and so forth. It's all awesome. That's why EVE defines MMOs for me.
What games would you say defines genres? You can disagree with me if you want.