Most likely a drain has dried out and there is no water in the trap to stop the gas from coming up. Sink, shower, or main floor drain.
If you think you smell sewer gas in your bathroom, it could be that a sewage blockage is in your pipes, causing the sewage to back up in the lines.
I do not know why this is happening, but this has nothing to do with Poptropica. Please post questions in the correct section.
Change the wax seal under the toilet
Sewer smell from toilets or some other problem
You may need to replace the wax seal under the toilet.
Sounds like the trap in the sink is getting the water pulled out of it. It probably wasn't vented properly.
What makes a bathroom drain smell, soap makes a bathroom drain smell
Awful.
Awful.
The trap in the drain line under the sink is dry. It should have water in it to stop the smell
Lime
Your basement smells like moth balls because you either have the camphor smell throughout your basement or your wall contains the chemical agents in moth balls