Beating the troll boss?
 

http://i.imgur.com/TKCv572.png

The note in the other room says if you hit him 3 times or do a spinning attack he'll knock you into a wall, but this rarely happens for me (1 out of every 20 times maybe?). Bosses usually aren't this time consuming, is there anything I'm missing?

It took me a really long time to beat him too. What I did was backed up against a wall, let him come at me, then hit him with my sword before he swung his club. If you do that enough times in a row (without running away) he should throw you against a wall which makes a rock fall. Throw the rock at him. Repeat this like 5 times

There is a troll boss?

This is Classic, not iClassic.

just slash your sword non stop and it should work

^^^^^^^^^^