Yeah, till Win9x's API and DirectX came into play, DOS-era programmers were forced to write different drivers, to support specific hardware, for a single game. Sound Card support being the most common example.
Later Dos games made use of somewhat early DOS APIs like this DOS4GW written to take advantage of memory implementation in programs in newer systems. Other example being the Universal Vesa Bios Extension (UNIVBE) driver for graphics. Instead of writing drivers to access the hardware directly, the programmers were able to make use of these, like the UNIVBE, which behaves as the mediator between the hardware and the software.
But even with the presence of these, games still suffered from a multitude of unforeseen hardware-driver incompatibilites. Especially some TSRs, as swaaye mentioned. TSRs were dreaded when it came to Dos games those days, even though they are extremely useful otherwise.
Many games came with some sort of BOOTDISK creator or a guide to create it in the manual to help run some games which are very picky with what TSRs and loaded drivers were present concurrently. These were intended to run only the most basic elements needed to run the game, and nothing else.
As for the uncyclopedia thing, I wish they remove any resemblance to the Wikipedia website. And I also hope the search engines will NOT list the results in the beginning page. Newcomers and unsuspecting individuals will be falsely led to the site. The site may be fun to read, but the site should also have a permanent banner on top and bottom of every page mentioning "Warning: This site is a joke in the poorest taste. Read at your own discretion." Most of the "info" available there seem to come from half-baked dimwits and/or school/college dropouts.
