I think I'll take this time to set you all straight while it's still kind of on-topic. Note that any use of "you" is not directed to anyone in particular.
Casual gaming: When you play newer games designed by Nintendo to be easy to play, even when you have no prior gaming experience
You play Super smash Bros. with your friends because it's fun? You play through Ocarina of Time again with no intention of getting a record time for a speedrun, and just to enjoy it again? Guess what? You're a casual gamer.
Hardcore gaming: When you play a NES.
I wouldn't say "hardcore" is appropriate for a gaming class. There are things you can do and be hardcore, like beating Classic on Intense without dying or translating MOTHER 3. Me, I guess I play Super Mario World in a hardcore manner... but you should see me play a standard first-person shooter. You are not hardcore, but some things you may do are. And I apologize for repeating myself, but you are definitely not in any position to call yourself hardcore if you think Super Mario Bros. is hard.
Pro: No items. Fox only. Final Destination.
Pro gamers play video games for money, most usually in tournaments. A game tester who gets paid for it--that's a profession, so a tester is a professional gamer.
So what do you call people who only play Nintendo's new, easy-to-understand games? I think they're called non-gamers, but considering that these games have only begun production as a sort of experiment by Nintendo, you could call them lab rats...