This episode is amazing, it nails the atmosphere, it nails the comedy, and is the definition of going an extra mile. They didn't have to add all of these weird characters, they didn't have to have all these different design choices, but they did anyway, and it all just really works. Plus, foreshadowing to the end is always appreciated.
The setup to this episode is quite decent, but once Patrick leaves the plot, this episode gets really annoying. Most of it is just SpongeBob attempting to get on a bus, but the bus ends up leaving when he gets to it, and it's repeated a lot, and it's not funny, rather really annoying. Honestly, I don't think they used the concept to their advantage, as we didn't get to see much of Rock Bottom, aside from the setup.
I watched it again now. I used to hate this episode as a kid, but after rewatching it around a year ago, I find it amazing. This is classic episode. The atmosphare here is one of the best around the show. 9.5/10