It was quite something to wander through all those ruins and tombs at the time, taking in some of the brilliant environments; a classic being climbing to the top of the underground Sphinx in TR 1 and just looking around.
Now, the earliest games are supposed to have aged badly - not just the blocky graphics but the clunky, grid-based tank controls, something shared with Resident Evil. Once you've become used to the finer control provided by an analogue Dualshock, reverting back to 90s-style controls would be frustrating. I'd recommend you play Anniversary, which is a HD remake of the first game, and fantastic nostalgia. Because of the more modern analogue controls, it also feels a lot easier than the original.