Here is a save with lvl 20 guild: https://paste2.org/420FKOIk
Copy all the text into a text document and then import it.
WARNING: You will not be able to actually play on this save until 10th of july(but you will get the badge), so backup your old save before if you want to play the game before then.
It seems like the game has a memory leak that is causing all the lag. Just closing and reopening fixed the lag for me. The game has a checkpoint every 5 levels so you shouldn't lose too much by doing this.
 "Incremental Epic Hero 2"){kind=icon}
 "Dude and Zombies"){kind=icon}