Board Game Arena

Or does the game balance by making enemies stronger if more players?

If I understand the rules you'll still play 3 fight cards per turn, no matter how many players (so with 4 players, one player does nothing per turn). But yeah you have more health available in total. Maybe the hassle of dealing with 3 other people makes it harder again

You'll also be rotating first player, which has some effects on gameplay, such as where some damage goes. That along with some monsters dealing damage to all beheaded means that you might see damage coming in faster from both sides.

More player = more HP and more equipment.

it's more or less balanced, but you do have more options with more players.

Either way you still play 3 cards per turn.

Consider also that with fewer players, the players tend to be more geared up, as they won't need to compete for scrolls or gear