wombat was so dead on about the iphone/3ds thing. Iphone games are the dollar menu at mcdonalds. 3ds/psp/vita games are actual meals. Both get the job done but one provides a more rewarding experience.
I'm an IPhone owner and even though I bought a bunch of games on sale for $1 each (board games published by EA, Angry Birds, etc.) if I want to play a GAME, I'll bust out my PSP. I view IPhone games a step or 2 above Facebook games, call me a hipster if you want.
Worst IPhone game experience? Trying Oregon Trail again recently after all the updates made the game IMPOSSIBLE to beat unless you spend real money on items. 2nd worst experience: Slogging through the original ME IPhone game (the one that introduced Jacob and Miranda) promising unlocks for ME 2, and all it did was open 1 extra dialog tree line in ME 2 when talking to Jacob.
Best experiences: the OG version of Oregon Trail from like 2009 when there weren't extra add-ons to buy, and the Ben Stein trivia game.