Charming, casual fun, marred by bugs
In Bus Driver Simulator, you get to drive a bus in one of two cities, one in Russia, one in Germany.
On the plus side, the game really is charming. While its graphics are obviously not made with an AAA budget, they are well-crafter, with a noticeable, loving attention to detail. This is true both for the buses, of which each is modeled after a real-life equivalent, and the cities, with the various neighborhoods being distinct enough.
It's also nice that you can either play "career", driving either pre-made routes or ones you make yourself, setting how long you have to reach each stop and even what time it is, or "scenarios", where all parameters are pre-set and you have to earn a certain amount of money to succeed. (Obviously, you get money from ticket sales but are fined for collisions, arriving too late, departing too early, driving off the road, etc.)
And it really is quite chill, driving around in a big bus.
On the minus side, unfortunately, the game is rather weak, tech-wise, with some serious bugs and lack of foresight possibly ruining your enjoyment. With certain route/bus combinations, you can actually get hopelessly stuck on tree branches hanging onto your lane; it sometimes happens that the game doesn't recognize that you have arrived at the last stop (the rectangle indicating where to park remains green and passengers stand up but don't get off, but if you try to leave the stop, you get the "missed stop" penalty), making the route unable to finish; sometimes, AI cars stop at an intersection as if there was a red light even if there is no traffic light at all...
All in all, I think the game is worth its introductory price, or a similar one, if it gets a discount later on, but not its full price.