On how it hasn't aged well?

NV looked pretty dated even for the time it was released. Personally that doesn't bother me much but I have had a lot of issues with corrupted save files and game crashes. To me that makes it hard to recommend, but it's still the best first-person Fallout... If you get it running properly

The gunplay is nothing like a modern FPS. Hitting your targets depends on your character's stats, and is only somewhat related to where you aim the cursor. You can aim right at something, but if your skills are low, the bullets will curve and miss, and the inverse is true too - with high skill, your bullets aimed off-target will curve to hit.

There's no sprinting - your movement speed is locked to 'mosey'.

It crashes a lot, and some saves crash immediately when loaded, so you need to save often across a variety of different save files to avoid losing too much progress.