I'm not seeing a strong connexion to the theme, but the game in itself is fun.
The controls feel good, and the fact that you have to slow down while reloading add some depth to the gameplay (as you don't want it to happend when ennemies sourround you)
The power-ups are good too, and I liked the fact you have to get back into the mass of ennemies to get the little blue pellets, instead of them going directly into the bar up the screen
Nice job =)