What about the replay value of this game? It has only 5 scenarios.

And a scenario generator.

You will need to rely on the community or expansion packs for replay value.  The scenarios, (I've only done legend 1 and 2 so take it with a grain of salt) are very methodical/mathematical…meaning, once you figure out the "trick", there really isn't a lot of variation in achieving success.  This isn't a game where the 2nd playthrough will be a different experience than the first.  Only slight things will vary.

It is challenging, I might add.  Legend 1 is not a pushover and Legend 2 is tough.  It is a time limit game, no opportunity to explore, or camp at the castle and defend it and level up.  You must move, you must move fast, you can't kill all the creatures (because killing them moves the timeline and accelerates the end game).  You have to focus on your objectives and make key decisions..you have to allow monsters to penetrate your castle because that will be most prudent for achieving your objectives.

Legend 3 may solve your concerns. It has a ton of random setup and objectives that give you a different experience each time.

-There are 15 monster tiles which place or move monsters on the board. You draw 5 at the start and draw 5 more over the course of the game.

-There are 10 fate cards which give objectives that must be completed. The Heroes each draw one at random so your goal each game is different - sometimes the Heroes have to complete things on their own and sometimes they have to work together.

-There are 4 Dark Magic card0, one of which is randomly chosen as the final encounter once all heroes have complated their fate.

-Medicinal Herbs and Runestones are placed randomly. Of course the fog tokens add some randomness as usual.

-The event deck adds a low level of randomness,

There are also options to make legend 3 more difficult, by shortening the legend track by 1 or 2 spaces, giving you much less time to finish your goals.