I think the game does a really good job of being fair actually. Sure its hard, but there is always a solution, and usually multiple solutions, to each encounter.
I actually got bored of the game because I ran out of ideas for handicaps to make the game challenging. To start with, I essentially always play the game with a delayed start penalty, no special attack, no struggling, no moving forwards during i-frames, and no sliding. Even then, you can still reliably beat the game without any resets, it just takes time to master each mechanic and enemy. Once you start seeing the solutions to each encounter, you may realize that the game is far more forgiving than you'd expect!