Editing Plist files

I'm not one to usually cheat in a game, but in this case I'm making an exception. This weekend, my roommates and I are having a video game party (which will simply be awesome, let me tell ya). One of the games we've bought is the great game Peggle. As much as I would like to play through every level and beat it to unlock everything for the party, I've been trying to edit the plist file to accomplish this.

I've found a few items within it that seem relevant, but haven't been able to do it. Two properties, and/or might have something to do with it, and so I put in "50" as the value for each. But when starting up the game, it just reverts the file back to its original amount.

Any ideas? Thanks.