The "Download Now" link directs you to the iTunes App Store, where you must continue the download process. You must have iTunes installed in order to open the link, and you must have an active iTunes account to download the application. This download may not be available in some countries.
From Differential Apps:
The positrons are floating around. There is a large abundance of them in 3 areas nearby. Why not take some electrons and make some fireworks, eh? The result of an electron and a positron colliding is a photon. Annihilate as many as you can before they reach you.Features: Easy, one button control Awesome 8-bit graphics! Retina display support Optimized for 3GS and iPhone 4 Game Center leaderboard and achievements Rad animations from the annihilation! Amazing background music Arcade gameplay style Two different enemies 3 distinct regions to play Game Center leaderboard and achievements Cool effects Get Positron today!Multiplayer soon to come!