Very creative game! I really wasn't sure about it at first, because the in-game help wasn't working for me, and you wrote "S" instead of "D" in the game, but after reading the game page and the comments, I gave it another shot. I'm glad I did! It's very satisfying growing your army over time, and I had tons of bullets flying at the end.
I think the controls could use some work, and I'm not sure I care for the music (it's a bit grating to my ears), but it's a very solid entry. What a cool concept - well done!