Topic says it all, it was working fine earlier today, I quit the game, left, came back an hour later, started it back up, and there was a crackly noise over the sound. Using Ubuntu 10.04, purchased from Humble Bundle.

Reboot? Try deleting the lib32 folder so that the game will use your system's default libraries.

I've had this happen in the past, and just had it happen again and finally solved it, at least if you're running 64-bit Linux.

It ran fine from the compressed archive, so after playing around with things I realized my launcher was apparently running the 32-bit version.  Instead of running /opt/WorldOfGoo/WorldOfGoo.bin32 run the bin64 and that will hopefully solve your problem as it did mine.

For some reason the DEB is no longer putting the shortcut in my Gnome menu.  Regardless, it should have placed a shortcut for the 64-bit version there and not the 32-bit one.

I'm running the 1.41 version.  Maybe this is a bug in this version.

Normally, the game is run by starting /opt/WorldOfGoo/WorldOfGoo, which is a start-up script that figures out whether you are running a 32-bit or 64-bit OS dynamically and sets up environmental variables accordingly. This script is also what is started from the Gnome menu, so there were never different menu entries for different versions of the game.

Unless the output of `uname -m` is different from the expected x86_64 on your system, I doubt that the script launches the wrong version. Instead, what you are probably seeing is problems caused by versions of libraries bundled with the game. Those are not used when you circumvent the start-up script by calling WorldOfGoo.bin64 directly.

If that's the case, the patch posted here may well solve your problems:
[patch] Game not starting on Mandriva 2010