@TreeSlayer7: The only way to fail is to have the first and last colors be different. This obviously isn't the case if the string is empty, so the empty string passes. So does single Blue and single Red.
Advice: choose only two weapons to upgrade. Bazooka for area/explosive damage, and either assault rifle or sniper rifle for aimed damage. Shift just between those weapons using the shift key. Don't upgrade the third weapon until the first two are fully upgraded. I like the following talents: More Rubies > Regen > Hearts > Medpack/Faster Horse. After all upgrades, reset talents and ditch More Rubies. I am not sure if regen tops out at a maximum rate, though.
I am glad that they gave badges, since it gives me a valid excuse to play it again. Not just my own pleasure and enjoyment, but BADGES! So my Utility is greater, and it is a Moral Imperative that I pursue it. And Kong has lived up to their part of the Social Contract by giving badges.
Thanks for the game, for the badges, and for getting to hear good music and NONSENSE!!! shouted repeatedly.