My friend and I used to do the same thing a Visitor Q but without the beer. In the arcades, we burned through a lot of quarters, soda and pop rocks in all night binges to try and get to the end. When I got an NES and the game cart, we blew an entire summer weekend, 48+ hours, zero sleep, with ass loads of soda, KitKats, Little Ceasers pizza, two tubes of BenGay (for the
Nintenditis) and chicken's blood (for the inevetible, "oh ---steaming pile of meadow muffin---, I bumped the NES," which, thankfully, never happened). We never did get to the end if there was one. I've seen people talk about Gauntlet ending at levels like 999 (arcade) or 500 (NES) but I've never confirmed it.
The only version of Gauntlet that I know of with a true ending was Gauntlet: The Third Encounter for the Atari Lynx.