Thanks for bringing this to itch.io - cogdemos is great but for me the save system is useless - takes me back to the very start of the game every time an author updates.
I would suggest though that as you get closer to release that you get a person with a stronger grasp of English (any variant) to give you an edit pass or two - especially if you plan to sell the game via hosted games.
Adding my two cents on this, unless coded specifically, the saving thing corruption of the saves happens here as well; no matter if you use cside or twine, if something that has been previously done is changed, that will corrupt the save either way, so you'll always have to start from the beginning.
Now, if we're talking about a fully released game this doesn't happen, but for wips? It will happen most of the time
