Haunted House is a curious games of many firsts. It's among the very earliest graphics-based games to try to emphasize a horrific theme, and (according to Wikipedia at least), it's one of the earliest games where you can scroll the screen, as opposed to earlier games where the screen scrolls automatically in some racing games.
It plays a lot like
Adventure, collecting items and bringing them to specific locations all while avoiding baddies (spiders, ghosts and bats, oh my!). Despite coming years later and only a few Atari games attempting an action-adventure formula (the previously mentioned Adventure, and
Superman come to mind), Haunted House falters for a few reasons.
Generally, you have the option to turn on a candle to try and find keys, stairways, items, and other things. Some items are strictly for progress, others keep some baddies away, and others are to be taken to the front room to complete the game. Unlike
Adventure, the rooms are not shaped in any sort of maze outside locked doors so it's a lot of samey looking areas that are only marked by colour and floor differences, in harder difficulty levels, enemies behave a bit different and you got to find more keys, but for an adventure game, the exploration factor is a bit null with the samey areas.
Adventure's graphics are more primitive, but even just stumbling upon a new castle, or finding your way through a maze is a bit more satisfying than the invisible item hunt of
Haunted House.
For those exploring the roots of early adventure games or horror-themed games, you can do much worse and much more frustrating games, but it's not going to win over any hearts unless you eat, breathe, and sleep Atari 2600. Be sure to read the manual first to get the most out of this!