This is a very addicting game, but having a leaderboard or achievement system will definitely help bring people and keep them. Also, two small cosmetic fixes: put commas with the numbers (hard to figure out how much money/units I'm getting with each upgrade) and army size in the cinematics to match the different sizes. I'm not saying put 3 billion creatures on the screen, but if they have 3 billion and I have 12 billion, show me having 20 units and them having 5.
I have some problems with the achievements in-game. I have completed a few of them, but it says I didn't. But, overall, amazing game. 5/5 and its being put on my favorites!
 "Immense Army"){kind=icon}
 "Smoking Kills"){kind=icon}
 "My \"Dear\" Boss"){kind=icon}
 "Geek Mind"){kind=icon}
 "Learn to Fly 2"){kind=icon}
 "Flood Runner 3"){kind=icon}
 "MegaDrill"){kind=icon}
 "Sushi Cat The Honeymoon"){kind=icon}
 "Defend your Honor!"){kind=icon}
 "Platform Racing 2"){kind=icon}
 "Multiplayer Snake"){kind=icon}
 "SAS: Zombie Assault"){kind=icon}
 "Kongai"){kind=icon}