1. Excessive Blocking
A gimmick like this can turn what should be a simple enemy into a nigh-insurmountable challenge. Not that there's anything wrong with that, but when you have 6 nigh-insurmountable challenges surrounding you, all of a sudden Easy Mode starts looking pretty prime.
Why YOU Have To Do It: Part of the fun of platformers is your remarkable prowess. You can take out a room full of enemies if you do it right.
Problem is, just because you can kick copious amounts of ass doesn't mean you can put up with a lot of damage. Hitting a common opponent a dozen times isn't that odd at all, but getting hit a dozen times is always bad news. If you don't block, you die. Plain and simple.