Thank you for playing! Sorry to hear about the lag, we're currently working hard on a big optimization + compatibility patch to mitigate (hopefully!) most of those issues.
As for the shotgun, I completely agree - a complete overhaul is in the works regarding those issues. It simply does not feel like a shotgun in it's current stage. We want the Net Gun to have a unique identity whilst still having that super shotgun feel - just ironing out the creases.
I'll have to check out Shanghai Gold, it looks awesome