Hi there, no problem:) The mobile version has a bunch of new weapons and items, but those are also present on the PC version! To name a few, Singularity, Clone Pod, Sweep, Totem, etc. The new shopkeep item drops were also added in that update!
As far as the next update goes, I'm planning on adding a second world with new enemies, as well as new weapons, items, a new boss, and a new secret shop with its own unique items. I'm sort of in talks that I don't really want to reveal right now, but hopefully soon I'll be able to start working on the new stuff:) Congrats on the speed run by the way, that is wicked fast!!
Also, about that lag... I'm not really sure what could be causing it off the top of my head, but I do want to look into it and see if I can figure out what's going on! Do you mean that the game lags when you're in that specific scenario (fighting the shopkeep using Zap, Missile, Singularity, Sweep, or Doorbuster), or do you mean it lags when you fight the shopkeeper and whenever you use those weapons (regardless of who you're fighting)?