Is it to be a multi-player game? If so, you won't do it with HTML and JS alone. You will need some sort of server-side support.
If a single-player game, you can do it all in JS. Just don't offer any big prizes, etc. for doing well, because hackers would simply download all your code (no protection against that, though you can obfuscate the code) and figure out how to beat the game.
As for "flavors" of JS: I can't think of any you would care about if your game is truly text-based. MSIE versions 8 and below (and especially 7 and below) have some peculiarities. You are unlikely to run into them with a text based game, bui if you do, just ask for help. It won't be a big issue.
An optimist sees the glass as half full.
A pessimist sees the glass as half empty.
A realist drinks it no matter how much there is.