It’s a huge improvement over the original. They’ve made a bunch of balance improvements without infringing on the unique identities of each civ (which is unfortunately what happened when they tried to do balance changes to the 2013 Extended Edition). The graphics are all new and now look how the game is in your nostalgia, rather than…how it actually looked. You can build bigger armies, and reuse god powers (for a cost). There’s improvement in quality-of-life features, like modern hotkeys, as well as tools to assist with scouting and eco management, if you’re a lower-skilled player who gets overwhelmed by all the multitasking.