Really? i found Eve to be easy to reach Satan and kill him.
The fact that Eve's starting items can only be activated by taking damage (the exact opposite of pretty much the only goal in the game besides "shoot bad guys") is already a bad mechanic. She is then given abysmal stats and becomes completely reliant on getting lucky in item rooms, something which she doesn't seem to be able to accomplish on almost every run I make with her.
Life is especially precious when you have almost the lowest possible damage stat in the game (actually, can you even get to 0 bars in the damage stat? If not, then Eve's damage is actually the worst) and need to survive as you take out enemies painfully slowly. It's not something you can just give up when you need extra help from the Dead Bird or Whore of Babylon, which often don't help fast enough for you to have a good probability of survival.
Edit: Due to an extremely lucky run including Robo Baby, Sister Maggy, level 3 Meatboy, the Book of Revelations, and a Battery, I managed to beat the game with Eve painfully slowly
Three achievements remain