No revenue estimate for GOG — its rating/review counts don't calibrate to sales the way Steam's do. The Steam version is estimated at $4.3K — a different platform, not this one.

The Summoning

The call of magic and mystery is irresistible. Heed it and revel in the glorious excitement of The Summoning. "The power of the Shadow Weaver grows each day and the pall he casts over the world expands relentlessly. Even as I speak, we are under attack by his Hordes. There is no time to teach you more of the art of casting magic. And what weapons training you've received these last months will have to suffice." The beautiful mage closes her eyes but for a second and a blinding flash of light engulfs you. Just as abruptly, the brilliance collapses and you find yourself in the labyrinth of Shadow Weaver's dreaded stronghold- ready for the adventure of a lifetime! A single-character fantasy role-playing adventure of the first order. The Summoning delivers a mesmerizing, intricate plot with shocking twists and multiple endings. Play inside a huge game filled with mazes, castles, secret passageways and dungeons. Teleport to alternate dimensions. Gather clues, unravel puzzles, meet and converse with a multitude of fascinating NPCs, and battle hordes of menacing monsters. With 40 levels, you're guaranteed over 100 hours of breathtaking fun and excitement! Heed The Summoning and enjoy the rich rewards of fantasy role-playing and action adventuring classic at its very best!