I can see how it can appear to be like this in the early bloodlines cause you can get away with even just using block breaks all the way. In the first ten bloodlines or so, the only real challenge is the God King. But don't be deceived, each bloodline enemies get slightly faster and more difficult and all the easy bloodlines are great training to gradually get your skill up.
Infinity Blade is actually pretty deep in terms of the techniques you have to master to beat enemies at later stages in the game. Here are some tips from the developers:
http://www.epicgames.com/infinityblade/devtips.html
And here's a few things I didn't realize in the beginning:
- parrying is the most fun and important skill to master, it requires you to observe your opponent very sharply and the moment he's about to strike at you, you should not only swipe in the opposite direction but make sure that, at the end of your swipe, your finger touches his sword (master this and parrying starts to feel really cool and intuitive)
- how you time your blocks and dodges seems to give you stab opportunities, the easiest thing is always to hit block/dodge long before it's actually necessary but I'm noticing that when I hit i.e. dodge just in time, I get a stab opportunity
- attack A LOT, waiting around for your opponent to make his move is often good too but it's often better to be swiping like a madman because it 'scratches' him and, if you're timing things correctly and adjusting your swipes to his stance/moves, it'll often make parrying easier
Perhaps the game may become more enjoyable to you as it gets more difficult. For me personally, it's by far the best game on the platform atm. I'm at bloodline 27 now I think and I'm still having a blast, especially with how fast and fierce the enemies are at this point.