How did you jump to this conclusion?
Hmmm?
There are different mechanics for each game, and they can all be fun in their own way.
That doesnt mean it is needlessly "complicated". The amount of moves is irrelevant to the kind of moves performed and the style of play. Is that other game fun?
It may basically look the same on the surface like a hack and slash title but that doesnt make it the same or similar. Btw hack and slash are basically games such as Dynasty Warriors and this doesnt play like it. HS should belong in the action adventure genre mostly.
Read this too:
http://ps3.ign.com/articles/804/804704p1.html
Your friend may also need some practice because he is used to that other game. You cant expect every game to play the same. Its just not logical.
I tried Ninja Gaiden, DMC and God of War and they all play differently, each game having different difficulties and complexities. I cant use the same inputs or tactics
What was that other game btw?