Reisen. If my Google searching is reliable, it's a German word meaning "to travel". And that's certainly what the star of the Reisen series, Sneedle's lovely 10-episode adventure puzzler with hints of escape, has tasked herself with doing. (The preceding link and the image link go to a list containing links to the ten games. The play buttons below link to the individual games.)
The Reisen series catalogues the tale of a small red-headed girl named Jitter, who recently lost her parents to the war (World War II, most likely) and wants to go see her grandmother. This is easier said than done, as at the story's beginning she is confined to a bunker far away from where her grandma lives. If she wants to make the journey, she'll have to be cunning and resourceful, doing everything from trekking through dark forests to pole-vaulting over deep water to getting guards drunk.
Every game in the series can be played (almost) entirely with the mouse, using an interface many should be familiar with. Navigate by clicking the yellow arrows, and click on objects to interact with them and sometimes pick them up. If something is in your inventory (the column of circles on the right), click it to select it, then use it on the environment-- or on the "+" in the corner to examine it up close. Your goal varies from game to game, but just focus on doing what you can and you'll get there.
This is a series with good points and bad points, like many others. The visuals are relatively unimpressive, the puzzles are okay in the logic department, and pixel-hunting can get annoying, although it gets much more tolerable later in the series. What really makes it worth playing, though, is the story. Jitter's tale is an epic one; she meets many allies and enemies throughout her journey, and has her share of both comedy and tragedy, plus a few philosophical discussions about war and humanity.
If you've got a large block of time to kill and don't mind mature subject matter, playing the Reisen games back to back is a good idea.