There are "quests" in there. They're called challenges.
Even if it's not an MMO, it does have some RPG elements.
No, cause then any game with an "Achievement" system would mean that they all have RPG elements, simply no.
RPG=You play a character and go through his story until the end. You see character development, story twists and changes, etc. Basically, you are seeking the depth of the character's background, the world and its current state, and how to solve the problem.