I always read bad opinions about this game and never played it. Now my 5 years old son discovered it on the shelf lol

and we tried it together. Surprisingly, it seems playable, at least, not worse than Temple of Elemental Evil.

My son, playing barbarian, manages to kill some orcs and undead in the beginning. Now some features are a bit odd to me, for instance, the character moves quite slowly. So, I'd be grateful if U could advise me some tricks to enhance the overall playability.
Thank U in advance,
Yigor