I enjoyed playing Superbrothers, but it was the kind of game I only wanted to play for thirty minutes at a time. That might have more to do with the genre than the game itself, though.
The best part is undoubtedly the music. The delivery is good too; just experiencing the world is half of what the game is. Visually it is hit and miss; the pixel art looks great however there are often parts that are too detailed and stand out for it, such as the sprites. And the combat reminded me of Quest for Glory, which I enjoyed.
The game doesn't try to hold your hand too much, thankfully, but reading over the Megatome can always put you on the right path (and adds to the experience besides).
What I didn't like was the very obvious touchpad controls. They work completely fine, but the game could have been made more enjoyable with better mouse control rather than just substituting the mouse pointer for a finger. Also the blatant twitter integration was groan-worthy... but I could accept it with the way they presented all of the dialogue.
Ultimately I'd say that if you are interested in Superbrothers that you should try to catch it on sale. It is good, but completely skippable.