Click the green flag to start the game. Use the left-right arrow keys or A and D keys to move Godzilla. Click on the buildings, the helicopter, or the very small crowd of a military dude, and 2 normal folks to destroy them. (I could have given them a gorey touch but remember, this is a kids website.) Press space to use the atomic breath. (Sorry if he is more greenish than blueish when he does that.) He will do it for 1 second plus a 5 second cooldown. When you destroy all known things in the game, well, congratz! You "finished" the game. You can always click on them again to destroy again.
To be safe, I found a lot of people who made games like these, but most that stuck to me are, Godzilla Devastation by fredbarborosa (mine was pretty much the same except there wasn't a King Ghidorah, and there wasn't a crowd or helicopter), and what inspired me to make this game was Godzilla by Dreamcast. (In case if you think this game is bad, this is my first time making a Godzilla game.) Godzilla also is owned by Toho in case you didn't know...