Iron Jack 2 is a mashing-up of multiple kinds of genres; it combines platforming with some physics-based gameplay and places them inside a familiar "beat levels, get three stars" box. You play as a lone spaceman whose job it is to collect fuel energy. Once enough energy is collected,a level can be exited and completed.
This sounds simple enough, right? We've seen many games use this formula to great effect, making its players jump through increasingly difficult hoops in order to get that vaunted three-star score, and a place on leaderboards. It's a great way of encouraging replayability: instead of having to concentrate on making every level fun, you just make it competitive, instead.