Complex sentence: A highly simplified spinoff called "Spaceopoly" was published in 1997 by Valen Brost Game Co. Similar to "Risk", this game has secret mission cards specifying an assignment that the player can complete to win the game.
Split into simpler sentences: A highly simplified spinoff was published in 1997 by Valen Brost Game Co called "Spaceopoly". This game has secret mission cards, similar to "Risk", specifying an assignment that the player can complete to win the game.