The length of "Talisman"-like games are always going to be higher than other board games.
BUT I do not see this as a problem. Just like saying that a game like "Jungle speed" is too short.
These are not problems, they are part of the identity of the game.
However, you can shorten the gameplay considerably and increase player enjoyment by doing the following:
1- roll 2 dice for movement and choose whichever one you want. This will allow you to complete missions much faster and you are less likely to die because when you are low on life, rolling 2 dice and choosing 1, you are more likely to land on those corner spaces where you can gain more life.
2- lower the trophy level from 6 to 5 to get a relic and upgrade level. You will then find that in a few turns, players get their first relic. Especially with 5 players, within 1h30, most players should have 2 or 3 relics and be at level 6-8.
Change #1 or #2 on their own reduce the length of the game. Choose the two options together, and watch the game length halve.
With the new expansions Nemesis, we are looking at 6 players and more player vs player combat. So we are probably looking at longer games too.
Hope this helps.