What is an Adventure Game?
Colossal Cave Adventure (also known as ADVENT, Colossal Cave, or Adventure)[1] is a text adventure game, developed between 1975 and 1977 by Will Crowther for the PDP-10 mainframe. The game was expanded upon in 1977 with help from Don Woods, and other programmers created variations on the game and ports to other systems in the following years.
In the game, the player controls a character through simple text commands to explore a cave rumored to be filled with wealth. Players earn predetermined points for acquiring treasure and escaping the cave alive, with the goal to earn the maximum number of points offered. The concept bore out from Crowther's background as a caving enthusiast, with the game's cave structured loosely around the Mammoth Cave system in Kentucky.[2]
Colossal Cave Adventure is the first known work of interactive fiction and, as the first text adventure game, is considered the precursor for the adventure game genre. Colossal Cave Adventure also contributed towards the role-playing and roguelike genres.
https://en.wikipedia.org/wiki/Colossal_Cave_Adventure 

It is considered the first of all adventure games.
https://en.wikipedia.org/wiki/Adventure_game 
http://www.rickadams.org/adventure

You can play it online, to simulate the original text based computer games.
https://grack.com/demos/adventure/ 

There are even, still, walk throughs posted on the Net.
https://www.youtube.com/watch?v=O3etkSoHrR8 (no cheating)

A similar game, developed shortly after Colossal Cave, was ZORK.
It also can be downloaded, or simply played on the Internet.

http://www.infocom-if.org/downloads/downloads.html 
http://textadventures.co.uk/games/view/5zyoqrsugeopel3ffhz_vq/zork 
http://textadventures.co.uk/games/play/5zyoqrsugeopel3ffhz_vq 

Warmup: (ASSIGNMENT part I)
Play ONE of the following, as an individual:
Download and play Ken Plotkin’s DOS executable from:   
http://www.rickadams.org/adventure/e_downloads.html 
OR play Zork at: http://www.play.vg/games/104-Zork.html 
OR play Rogue at: http://www.freearcade.com/Zplet.jav/Rogue.html 

Other articles:
http://en.wikipedia.org/wiki/Zork 
http://en.wikipedia.org/wiki/Rogue_(video_game) 
http://jerz.setonhill.edu/if/ 
http://brasslantern.org/writers/howto/i7tutorial.html 
http://www.ironrealms.com/text-games-five-tips-for-writing-character-backgrounds 
You too, can write a text based adventure game.
http://inform7.com/ 
http://inform7.com/downloads/ 
Later versions of Inform allow pictures and music.

There are many online guides to writing in Inform7.
https://en.wikibooks.org/wiki/Beginner%27s_Guide_to_Interactive_Fiction_with_Inform_7/Getting_Started_with_Inform_7 

ASSIGNMENT Part II: 
DESIGN a simple game with at least 6 rooms, at least 6 objects, and at least 6 verbs.
ASSIGNMENT Part III:
Program your game.