Hello Evaneself,

The only DLC ever available for the Fran Bow game here on GOG is the Soundtrack Remastered as shown on the store page for the game.

That gamer's review is simply mistaken about bonuses having disappeared. Nothing Fran Bow related has disappeared on this store or any other.

If you are at all interested in the game, consider playing the demo, which is available here on GOG. And, of course, the game is currently on sale here, as part of the Point&Click sale, so this might be a good time to purchase, if you decide the game interests you after trying the demo.

I hope you decide to try the demo.