It sounds like you are very much the target audience so I'm elated to hear that you think it holds up against those games (which I am a fan of as well).
That's an interesting thought on the loss system, and I greatly appreciate your feedback. My first worry is that it could result in frustration with repeated early losses. The rationale for the current 3-loss system is: from what I can tell so far, the most fun part of the game is once your build starts to really come together and you can get some satisfying, optimized big spins (midgame), so I want to make sure most runs can make it to that point.
On reflection though, there may some other approaches that keep the tension higher while giving a good chance to get a nice run going (example: maybe the first 4-5 battles are all singleplayer and then the final few battles are the high-stakes pvp; all the while 1 loss means game over)
Thanks so much for checking SpinFighters out and sharing your thoughts!