Press Up, Right, Down, Left at the title screen (where you normally press A and B). The cheat menu will appear. Enter one of the following codes at the "Cheat" menu to unlock the corresponding cheat option.
Everything unlocked
Enter Nothing But Hope as a code.
Turn on Blox time
Enter Freeze Frame as a code.
All Colored Blox
Enter Rainbow Blox as a code.
1 million Boom Bux
Enter Bailout as a code.
All sound effects are Virus Blox sound effects
Enter Musical Fruit as a code.
All animations turn into flowers
Enter Blox Bouquet as a code.
When you get beyond a gold medal in Solo or Co-op modes, little gems will surround your gold medal and "Wow!" or "Great!" will appear. Getting all of these is a hard challenge, but with no rewards.
In the heroic levels where you are in the evil lair, hit the big robot that appears in most of the levels. This will make him shoot four rockets in the direction he was facing when you hit him. This is useful for getting the gold medal.
