Gauntlet, not a game for the faint of heart...
But in reality you just need to have two things to play and enjoy this game - patience (I can't stress this enough) and a love for the classic 'Dungeon Crawler' genre, which has paved the way to many great games in this modern age.
However - you will need to understand what this game is NOT. It is not item / equipment intensive (no matter how much some players will complain), nor is it a game that currently contains plenty of end-game material - and NO, this does not give you the right to complain endlessly when you realise this.
If you are looking for these sorts of games - then you can play a game like Diablo or Path of Exile, because chances are; you will not be able to enjoy this game or understand the uniqueness that it presents.
So what sort of people would enjoy this game? 'Completionists', classic gamers, players who have a group of friends and want to enjoy a co-operative game together (re-experience the 'old days' where gamers would sit together and play on a console), players that have played the Gauntlet gameline since the very beginning, fans of 'Dungeon Crawlers' - the list goes on and on.
It is a game that immerses itself within local competitiveness (just like those times when you would battle your friends in Super Smash Brothers) as well as giving you a darker theme (for the glory of adult themes).
Truely a game that can unleash a multitude of emotions.
Do I recommend this game? Yes
Should you buy this game? Yes
Would you enjoy this game more with friends? Hell Yes!
So leave your ego at the door, sit yourself down and play some Gauntlet.
(If you were looking for gameplay and mechanics information - go here http://gauntlet.gamepedia.com/Gauntlet_Wiki
--- EDIT --- 5/11/14
I have had a few messages saying that 'if I find this version of Gauntlet enjoyable - I must not have played any of the original games'. I laugh at these messages - and to refrain from any further pointless accusations, please refer to the below.
I have wasted many a 'gold coin' playing this game back in the arcades in the 80s (the original and Gauntlet 2) and I am currently arranging shipping to have the one of the original Gauntlet Arcade Machines - delivered to my house.
I have then spent many many hours playing the Nintendo version as well.
I have played the game on the Atari Lynx (Third Encounter).
I rampaged my way through number 3 - on the Commodore 64.
Legends, Seven Sorrows, Dark Legacy on Playstation 1 and 2 respectively.