My first experience with games (and one of my first memories) was with the Ninja Turtle arcade game. I was standing on my toes, staring upward, and savagely mashing the attack button in ecstasy. I was Donatello, of course. There is some inherent fun to be had from decimating countless waves of foes via an intuitive control scheme -- which is what Sky-Whirling Geo offers. Cowabunga.
The game's basic: It taps into that childhood power-trip of being a sword-wielding badass -- with wings even! -- that carves his way through a gulag of chibi baddies. You're a hellbent Pit from Kid Icarus, intent on causing as much bodily harm as possible. Since the game force-scrolls and has baddies appear at timed intervals, its structure resembles that of a shump. Because enemies appear in these designated waves it makes the difficulty stem mostly from the pattern recognition of enemy spawns (the rest comes from having a single life), but on Easy and Normal this shouldn't be a problem. It controls like a dream and enemies drop after one hit, which furthers your feeling of pre-teen 'coolness.' For some reason there's a timer at the bottom of the screen; since the game force scrolls this time limit only applies to the (easy) end of level bosses. Unfortunately, the game runs only a paltry three levels.
I'd like to see another game use this control scheme but with something meatier behind it (a mini-Metroidvania, perhaps?) but as it stands, the game's a cool fifteen minute diversion.