I found this while I was finding the Plants vs Zombies: The Movie. This is the secret level that can only be played if you use the Cheat Engine. How? Now we go to http://insaniquariumguide.com/, then click the button: "PvZ Guide" on the top, then help me find how to play level 6-1, I haven't find it yet. That page also contains how to play the MOD version of Plants vs. Zombies. So, wanna see the level 6-1? Here.