While looking stuff up for another post I found a collection of every coverart for every intellivision game. Some really fantastic art in here.
Intellivision Complete Game Cover Collection - Arcade Punks
https://www.arcadepunks.com/intellivision-complete-game-cover-collection/#google_vignette
Here is a complete case cover collection for the Intellivision I posted this last year…
I really liked this cover for Thunder Castle. Never even heard of the game but this is the type of fantasy art I crave. Gameplay doesnt look too bad either!