i think theres a bug at the moment, i'm at tier 7, and sometimes when i try to start at waves which ive done before (im at around 380000, and i tired to go to 300000 on insane mode), it showed much higher tiers, (ie tier 11, to even tier 75), when i pressed play. I tried a few times in a row, and then tried to start from round 0, when i did this, the tier was normal, and when i later tried to go to round 300000 on insane, it was the right tier
maybe you could add a way of replenishing protium in the next update? I have reached it, and it really makes things a lot more manual than with any other types, as you have to keep replacing it
 "Antimatter Dimensions"){kind=icon}
 "The Perfect Tower"){kind=icon}
 "Reactor Incremental"){kind=icon}
Huh, PM me if your save still doesn't work.