Fallout: New Vegas

What works

• The installer and launcher worked without apparent issue. I could correctly adjust graphical settings with the launcher.
• The boot sequence, main menu, and in-game settings are functional. I can rebind keys, adjust brightness and sound levels, and tweak game options.
• Starting a new game worked correctly. The BINK-video cinematic played perfectly, and I could create my character as desired. 
• In general, dialogue, VATS, combat, skill-assignments, perks, and quest progression are all perfectly functional.
• The game appears as stable as it is on Windows, with crashes at least as rare as I would expect on a good machine. Graphical glitches are rare after disabling HDR.

Fallout New Vegas is a very large game, with a known reputation of being kind of buggy! It can be hard to say at one point one is really 'done' with testing, just owing to the wide variety of mechanics and forms of interaction. There's fast-travel, physics, crafting, day-night cycles, character AI -- all seen working -- but still such a large variety of weapons, special interactions, quests, game endings, DLC and so on. Even a careful playthrough to the end is only going to capture one person's play style; and on top of that, the game is always marked by many small, random, unrepeatable glitches across just about every platform it runs on. Best I can say on those is that I've seen no particular excess of them!

What I can tell you then is that thus far, I have a very slow and thorough 5 hours playing as a patient thief-style character, specializing in melee, stealth, and survival. I've cut a very slow and winding path from Goodsprings down to the Mojave Outpost, completing roughly all that one can do in Goodsprings, its surrounding landmarks, the NCRF, and most of what one can do in Primm and on the road leading down to the outpost. The game has largely performed well up to what my expectations are coming from Windows!

What does not

• Enabling HDR via the launcher caused white flashing artifacts to appear on certain objects. Using either just bloom or disabling screen effects fixed this.
• Songs on the radio repeat far more often than normal. Although the in-game radio is known to be repetitive, as a long-time player of this game, it stood out to me within an hour of turning the radio on -- I can frequently hear multiple songs having been repeated three times or more in the past half hour. Within the second hour of listening to the radio, I'd heard two songs outright repeat back to back, the second occurance involving the song starting a third time before suddenly being cut-off and replaced with a new one. Other forms of in-game music all appear to function correctly and smoothly.
• Some dialogue lines will repeat themselves twice as well -- both the spoken words, and the associated animation.

Workarounds

What was not tested

A lot! Alternate playstyles, the vast majority of quests, full playthroughs beyond what I've experienced in just the first 5 hours of playing the game. I am very confident that I'm well past any very quick, easily noticed severe issues, and I feel very secure with moving forward with my playthrough and investing time into my character -- but it is still an open possibility that something goes clearly wrong much further down the line.

Hardware tested

Graphics:

• GPU: AMD
• Driver: open source

Additional Comments

• Initially, the in-game music did not work. This was due to missing the 32-bit GStreamer 'Good' Plug-ins -- once installed, the in-game music functioned.