I like the gamified approach. I'm starting to think of doing similar for some productivity ideas I have. Too much going on to start something new though.
Ah but you don't have to; there's a number of gamified apps out there already. It doesn't sound like you need any help with productivity if you've already got too much going on though.
Definitely a red ocean market.
I love games. I think they are (when done correctly) the single best way to motivate us to do good for ourselves