Minor issue, when click in the first evening on the desk in the lobby I get an error that 'sun' isn't defined.
Quick look reveals it get defined/assigned for the first time when/after sleeping by calling check_day (sleepstuff).
So I guess you should call check_day at end of prologue, before starting sandbox mode. Or use default statement to make sure all days of the week exist/defined all the time.
Found another issue:
Trying to visit the beach from the city (exploring), but get syntax error. The following line (script.rpy 16462):
if explore_beach == 0 and explore1 = True:
Can't assign in condition, should probably be 'explore1 == True' or just 'explore1' or removed completely. Since the menu choice already checked that 'explore1' is True :)