I don't know if you noticed but rich old guy appears again after you rush off the scene and then come back again. This is probably due to you using erase event instead of control self switching to a blank page. Hope this was helpful! Also the rat in the second town disappears if you manage to escape, dunno if that is intentional.
Also think it's a bit weird to have super fast rats roaming around town, unless the theme is that they're super plagued and hostile I don't think safe zones should have them in a game like this, just my opinion so far.
The big monster, the one that analyses u also transforms into another monster when you talk to it. I had this issue as well, it's because it needs direction fix.
Other than that the game is interesting, although a bit confusing.