I wonder if some of 'it's too hard' crying would have gone away if the game had made it clear in that first fight with the big dude that L1+up/down on the stick isn't just for avoiding grabs. It's far more useful for dodging attacks--especially against bosses--than the R2 avoid. You still need decent timing, but even if you mess up you're holding down block and won't get hurt unless your timing is completely off.
It's also not hard to unlock stuff permanently if you redo a level a bunch of times to 'get it right'. The game should probably have made it more clear that the XP you spend on permanent unlocks never resets; only the initial purchase does. So if you finish level 1 with 2500 xp you can buy the leg sweep focus move for 500, then buy 4x 500 permanent unlocks. Run level 1 again and the move will be reset, but once you get 500 xp you can unlock it again, then with another 500 you can unlock it permanently. If you're really persistent you could unlock all 500-750 xp moves on the first level without too much trouble. The 1000's could be done too I suppose, but it would be rather tedious since there's not exactly a ton of xp available in level 1 and you always waste the base cost worth of XP each time you re-run a level.
Also, I don't recall the game ever telling you this at all, but you can press right on the d-pad at any time to increase your score multiplier by 2. Score unlocks at the jade statue are pretty strong so there's no reason to ever kill any dudes without having 5x going.