Yarr, Gunjin. It looked cool, but I guess there's no mystery of what happened to it (or the other two).
As for retrocade, that was Ark's original plan for a bunch of old games (Pacman, Defender, Joust, Skate or Die, Jungle Hunt, and a deathmatch mode for Insanity) all on one disc. Instead, the Pacman and Defender games were fleshed out into full games that could stand on their own and the rest were tabled.
Is it too soon to add Saber Rider to the what-happened list?