Flop is relative term. If Super Smash Bros. Brawl or Final Fantasy 13 ended up selling a million, then they'd be considered extremely disappointing flops. Heck, even 3 or 5 million could be called a flop with games as big as those.
300k for a low budget game from a genre that died almost a decade ago because nobody was buying it anymore? Not the smashing success a lot of people were hoping for, but definitely not a flop either.