This definitely was a fun little browser game. If you want to keep working on it this is what I would add.

1) I clicked through the splash page too fast to read the instructions. So I was confused for awhile. I wouldn't mind having the basic commands persistent inside a floating box in the game for awhile.

2) I would like the ability to invite someone to play with me, in case the game is empty.

3) I would like a win condition, like if you hit 100 the game says you win and resets.

Did you follow a game building tutorial to make this, or was it entirely from scratch?