Great user interface, but the dynamics engine had problems. Part of a full suite of high-end engineering tools Prices somewhere in five figures. Most modern animation systems have dynamics built in. Sometimes it works. The first animation system with a dynamics package that worked at all.
Nobody seems to make money selling tools for game development.
But people keep trying. Great PR, but mediocre technology. They seem to have cut back somewhat since. As far as we know, nobody ever actually used their product in a game that shipped. Free demo versions of the base product, but actual use requires negotiating a royalty deal.