When I first owned an Xbox 360, the main game that kept me playing into the wee hours of the night was Hexic HD. Just the thought of it makes me tempted to fire up the 360 and return, but I'll resist, for now. On the surface, Gem Jam looks a lot like that addictive experience. It's not quite as deep, but it is a quite fun way to pass the time.
There's only the one mode of play here, but it sticks to its strengths. Players are presented with a screen full of gems with progress dictated by how quickly they draw lines through gems of the same color. That's all there is to it, to an extent. There's a payoff in terms of progress, though, with the more gems that are linked together creating more points, but also taking longer to complete. Given that short combos raise the progress bar faster, something that gradually trickles down, it's worth mixing things up.
As one progresses further through the levels, power-ups appear such as bombs to speed things up, and counteract that ever decreasing progress bar. It's consistently simple stuff, but Gem Jam is still quite fun to dive into. Such simplicity is aided by the similarly simple control method, working accurately throughout. Alongside that are some pretty crisp graphics that regularly offer feedback, such as when the screen goes brighter as the player nears failing the level.
A lack of achievements and a sole focus on leaderboards damages Gem Jam's chances slightly in terms of keeping the player interested, but it's a handy game to play from time to time. While some kind of puzzle mode would have really enhanced the replayability odds, Gem Jam still offers enough to be worth the $0.99 asking price.