WOW! I appreciate a lot you took the time to do this!
I think not knowing what to do is the biggest problem of this game. Maybe cause' i'm a solo developer and didn't have anyone to playtest, I saw the game easy and thought that just with a few tries, players would figure out what to do.
The checkpoints, I agree that I sould've added more to get better in the theme, instead of just reloading the same scene again and again.
Thank you for this great feeback,!!!
P.S: The acid part, you need to put the dog's food where it would get the dog to block the acid from exploding, and then give the drink to the agent.