Part of that's the game's simple concept -- a "cannon" continually pans left and right at the bottom of the play field, and tapping the screen fires a projectile. It ricochets off the top and sides of the screen based on your aim, then expands until it touches the edges or another sphere. Each of these orbs in space starts with three "hit points;" hit it that many times and it explodes. So, the goal is to ricochet your shots in a way that they hit multiple orbs and create longer and longer destruction combos -- all while avoiding the game-ending mistake of your shot going off the bottom of the screen.
Oh, and then there's Gravity Mode.
Gravity Mode is by far my favorite way to play Orbital. The rules are the same, only the larger the orb, the stronger its gravitational pull, meaning that it'll make your shots curve as they near it -- and paving the way for some really satisfying "trick shots."
A recent update to the game added Supernova Mode -- this play type tosses out the swinging cannon and instead lets you move it manually (with laser-sight accuracy). The orbs require five hits to destroy rather than three, and cause (surprise!) supernovas that hit neighboring orbs, making for even more elaborate combo opportunities.
The simple, yet addictive gameplay is matched with a stellar (no pun intended) minimalist, "retro neon" presentation, great music and sound effects -- there's even a robotic voice which, among other lines, utters, "That was close!" when you barely avoid your shot flying off the screen. It's a highly polished experience that I guarantee will absolutely get you hooked to the point where you're like me, unthinkingly tapping the screen to play again, and again and again ...
Orbital (bitforge, $1.99):
Orbital Free (bitforge, Free):
