Thanks for the feedback, always appreciate hearing from player's experiences and am grateful you've taken the time to buy and play our game. It's incredibly hard when developing games to balance these things - I've had other players say it doesn't offer enough challenge! And of course when you develop a game with no testing team gauging something like a final boss fight can be tough. Tricky but not impossible is the aim.
If I may offer some tips:
The electricity puzzle has an audio cue to help alert the player to when the gaps will be. Make sure to play it with the sound on if the timing is proving tricky and getting past requires only two full, swift turns of the crank. Patience and not overturning are key to this one.
Regarding the final boss - it is tough to get the last few pushes done. I've observed people playing and find that when players go full tilt right from the off they tend to burn out and this ends in failure. The trick to it is finding the curve built into the fight. The first few pushes really don't require much speed, so find a comfortable pace for the first few pushes and don't worry about taking a hit or two - use them as your cue to speed up. It's only the last push or two when you should be going full tilt and by that point you'll have gained enough momentum and have enough energy left in your arm.
Please don't give up, you can do it!! There's a little unlock for people that find all five endings. I'd love to hear if you come back to it and manage it.