Wow, thank you so much for your detailed feedback, I really love it! I hear you about hand fatigue. One of the first risks we called out while brainstorming this concept we dubbed "the claw" by forcing you to hold the click for long periods. Just a single click to initiate a line would have been a good idea to experiment with.
I'm thrilled you noticed the Pokemon Rangers comparison, I was definitely expecting more people to pick up on that! We had tons of influences, but that one was probably our core most influence in designing this game. We did consider drawing other shapes or drawing really precise circles, but discovered that it subtracted from the game feel we were going for: one of frenetic energy and fast and loose loops.
The trick to getting long loop streaks is to draw bigger circles! Everyone starts off drawing loops that are too small, but once you give them room to breathe your multiplier starts to go up. We wanted that to be an "ah-ha" moment for the player, but it was probably too subtle and not telegraphed enough. That issue is actually what inspired our "Ghost Line" powerup, which lets your loops pass right through enemies for a few seconds. Great for looping fast and letting it rip.
So glad you liked the art vision! Thanks again for your detailed feedback, it's super appreciated.
P.S. I played your game and really enjoyed it!