You can get hard-locked if you don't have enough money in the Mall after buying either the perfume or the necklace and have less than the money for buying whatever you saved for +5 zel for the subway ticket. There should be an option to walk back home at least. I had around 600 something zel, bought the perfume and now I can't leave the mall. Also, the fact that we cannot save during choices defeats the purpose of porting the game to Ren'py, it's as tedious as the RPGmaker version having to replay entire segments of the game if you inadvertedly go down a route you didn't intend to.