Is Talisman the same as or associated in any way with Heroquest?
While both games are 1980s fantasy settings and they share a few similar elements (and were originally published or developed by the same company), the game play is quite different between the two. 

With Talisman, players move around the edge of a board by rolling dice to determine movement distances. The player's choice in movement is limited to going clockwise or counter-clockwise. The player then follows the instruction on a location, often encountering and battling a monster for the goal of obtaining equipment or gaining Strength and Craft. The eventual goal is to complete a fixed sequence of events and obtain the Crown of Command. Expansions might add other victory conditions or opportunities for other exploration, but they do not really change this ultimate goal.

With HeroQuest, players are able to move around a board that defines a series of rooms and hallways, battling monsters represented by miniatures on the board. The game is more of a "system" than a fixed game, as it is intentionally designed so that players will play different scenarios using different maps and enemies each game, resulting in more of a board-game adaptation of classic fantasy pen-and-paper Role Playing Games (RPGS) like Dungeons &amp; Dragons.

Talisman was most recently published by Fantasy Flight Games (FFG) as the Revised Fourth Edition. While FFG has recently stopped publishing Talisman, it is still commonly available through many retailers.

HeroQuest was published by Milton Bradley, and while there have been several newer editions (including Advanced HeroQuest), it has not been republished in quite some time, so finding it for sale will be difficult (and expensive).

When researching HeroQuest, several different sources (Reddit, Board Game Geek forums, multiple game review blogs, etc.) frequently reference another FFG game for similar mechanics and play-style called Descent: Journeys in the Dark (Second Edition) so if you're looking for a HeroQuest-like game, that appears to be a common answer.