Fastar is a side-scrolling Action RPG game that packs way more action than RPG. Basically, you run as fast as you can while destroying any square that jumps in your way. It's all about speed and it's ridiculously enjoyable.
Fastar is so damn likeable partly because of its cartoonish graphics, but also because the gameplay is perfect for the iPhone. It emphasizes speed and is addicting as hell. Here's the trailer:
You can choose a variety of control options (tilt, d-pad, swipe) but the gist of the game is to kill all the squares that block your path (by tapping the heck out the screen) as fast as you can. But these squares are mean! They lunge, jump around, bounce back, and attack while coming in all sizes and difficulty levels. Along the way of your square killing quest, you can choose spells and upgrade your character's weapons and shields (this is where the RPG part come in play).
Once you master the game, it's a race against the clock to see how you stack up against the global leaderboard. Fastar has 24 different levels with normal missions, various quests and challenges sprinkled in. Pretty good for $1 [iTunes]