Q*Bert 3 was developed by Realtime Associates and released in 1992, and it was a bit of a missed opportunity in some respects.
Although it’s not quite Leaderboard, Chip Shot Super Pro Golf is a decent enough golf game on the Intellivision console. Arguably even the best.
Stadium Mud Buggies is a fun isometric racing game for one or two players. It was released on Intellivision cartridge by INTV Corporation in 1988.
In many way Stadium Mud Buggies reminds me of the classic Racing Destruction Set, or Rare‘s R.C. Pro Am, but it stands on its own two wheels as arguably the best racing game on the Intellivision.
Tower of Doom is a Roguelike RPG with mazes that must be explored and monsters that must be defeated in order to escape the dungeon.
There are seven different quests, of increasing difficulty, and the player can choose to play as any one of ten different classes (Novice, Warrior, Archer, Knight, Trader, Barbarian, Waif, Friar, Warlock, and Warlord). The ultimate aim is to reach the stairs on each level, and to keep going down until you reach the exit.
Diner is an unofficial/official sequel to BurgerTime, created by Mattel Electronics exclusively for the Intellivision in 1987. ‘Unofficial’ because it’s not really counted as canon, and ‘official’ because Mattel at least got permission from Data East before releasing it.