Dead on Delivery was a self funded game that was an experimental product at Rogue Rocket that wanted to see if we could marry some equipment collection mechanics to a relatively simple portrait mode mobile action game.  The result was that we ended up with a game that was super engaging, but for too small of a target audience.  Everybody either bounced out of the tutorial or first couple levels, or played everything through.  Ultimately it was a great little experiment that successfully reused some code from previous projects, and gave us a measurable result.