My boss just asked me what I think is the difference between a game and an interactive, and I stammered.

Here’s a more concrete reply:
“A game offers a form of play within a set of rules, which is ultimately decided by skill or luck.”

if the player has no options (no “agency”) then it’s not play, and not a game (You’re just stepping through a tour).
If you can do anything and win, then there were no ruleset (no limitations) and it’s not a game.
If there is no way to express your skill, or no influence from randomness/luck, then it’s not play.

I think it’s actually a complicated thing to define, but since we see babies and idiots playing games all around us, a lot of people reject the value of analyzing it deeply.

* At the Serious Games Summit back in 2011, a speaker had some really interesting thoughts on using games as a form of Metaphorical Learning: http://blogs.oregonstate.edu/warren/2011/10/07/spcday1-metaphorical-learning/

+ His talk was the first time I heard that it was common for games to require 3 things :
Randomness (dice roll/replayability), Restrictions (time limit/tradeoffs), and Rewards (points/gold/feels)
I’m on board with these 3 needs in my work, but the video game community hasn’t really agreed on any universal requirements.

* also, there was a really cool talk at GDC that same year, about defining the dynamics of games in the same way that we have defined moviemaking dynamics:
http://blogs.oregonstate.edu/warren/2011/03/24/gdc-2011wed-02-%E2%80%93-dynamics-the-state-of-the-art/

…
I’d love to rant on and on, but I know it makes “reading” my thoughts less appealing.