The late 90's were a hell of a time for gaming. PC games were in their prime, consoles were on the up, and good games were coming out left and right. One of the most widely-accepted "best years of gaming" is 1998, a year that brought Ocarina of Time, Metal Gear Solid, Starcraft and more. For me, as well as a lot of people, it is one of the most nostalgically pleasing times of my life.
Of course, trying to go back to those games now can be kind of hard. N64 and Playstation's 3D graphics look like absolute garbage now, pixelated all to hell and grimy to boot. On the PC, games like Fallout 1 and 2 and the Infinity Engine games (Baldur's Gate 2, Planescape Torment, etc.) had very complex game systems that required a lot of time to figure out properly. As someone trying to go back to play some early PC games now, it can be a hell of a thing trying to figure out these not-at-all obvious control systems.
Bioshock Infinite's lead designer Ken Levine thinks that games weren't just more complex: they were actually a hell of a lot harder too. To honor this period of gaming, Bioshoc: Infinite will have a difficulty mode lovingly described as "1999 Mode" in which everything has been ratcheted up in difficulty. Not many details have been given yet but he states that managing resources will be a much more demanding task and that a Game Over screen can actually be reached, a rarity in today's games.
I love when games make their difficulty options more than smarter, more accurate enemies and mess with health values. Crysis comes to mind as a game that truly made its harder difficulties different, by removing HUD elements such as the crosshair and making all enemies only speak Korean. If this mode in Bioshock Infinite actually alters game mechanics to make the game more challenging, I applaud the developers. We need less Veteran difficulties from Call of Duty and more Delta difficulties from Crysis.