A game to learn how to use the Linux command line

Question

I'm looking for a game that helps to learn the very basic commands of Linux/Ubuntu in a fun way (somehow like vim-adventures).

The game should be user-friendly to someone who has never touched Ubuntu before.

1. The game must run on Windows 8 or run online.
2. It would cost less than $100.
3. Must be character oriented.
4. Big plus if it contains a trial version before the payment (trying n levels for free).
5. Can be saved for playing in different times.
6. Must contain at least the very basics of the commands.
7. Ideally it would be 3D, but it is ok if it was 2D.

Answer 1

There is Terminus.

It has the following features:

1. Runs online.
2. It is free.
3. It is character oriented.
4. It saves automatically.
5. It contains the basic commands.
6. It is 2D

Additionally, you might be interested in this question: https://askubuntu.com/questions/337300/are-there-any-games-which-can-train-people-to-learn-terminal-commands