A new patch is live for Creature Card Idle on Steam, Itch.io, Kartridge, and Kongregate.
Previously, when you booted up the game, you'd be greeted with a black screen for a few seconds as the game calculated your offline rewards.
Now, the game will show a % indicating how far along the processing is.
This should hopefully improve stability on the desktop versions of the game (Steam, Itch.io, Kartridge) as well, as the game application itself is no longer unresponsive (from the operating system's perspective) during that calculation time. I suspect that this is what was causing many of the crashes that some players were experiencing when the game was starting up.
The change also affects the importer, so your game shouldn't soft-freeze while importing save exports anymore, either.