Honestly I'm in the same boat. I'm using Nim at work every day and the 30+ second build times for my project are a real drag (especially when working on UI and cutscenes, it's always _" move sprite by 1 pixel, recompile... oh looks like I need to move it down by 1 pixel too, recompile... maybe that animation should be slightly faster, recompile..."_)
I'm looking forward to all other improvements that V2 may bring, but incremental compilation is the single biggest thing that would make my life better right now.
