What bothers me (and, apparently, some other people too) is the "Achievements, Bonuses and Secrets..." - the Secrets part. I've fully completed the game on regular difficulty and bought everything from the store.
So... is ending and angry Kuraksa the secrets, or should I go back and pixel hunt more?
Indeed, the other character is an easter egg from my other Twitter account and requires pressing 4 blue squares from the title logo on the main menu in a particular order.
The Error screen requires to play around with the registry values for the game in regedit, but be aware that doing this leads to the deletion of the save file ^^