My thoughts thus far
As with so many things, the new Master of Orion now in Early Access (I insist on referring to it as MOO4, I /detest/ remakes that seek to supplant originals, even terrible predecessors in this case like MOO3) is a love it or hate it.
A lot of things remain true to the first two games ... MOO3, by contrast, seemed to turn its back on the first two in a lot more ways than MOO4 does. MOO3 seemed to try and take a darker tone versus the lightheartedness (relatively) of the first two ... light-heartedness is definitely back with MOO4, and I think this is best exemplified by the voice acting (-- your advisors/underlings all tend to be high-pitched in tone, and the goofy awkward [seemingly on purpose] GNN robotic reporters).
Some might be disappointed the turn-based battles of MOO1 and MOO2 are gone, battles are in real-time with limited controls (you can tell your ships where to go, etc., but they will fire their weapons on their own) so that is a bit more like MOO3, but I'm guessing that's a necessity for multiplayer.
There is already a nice polish to the game, the graphics are decent, but it is Early Access and there are some glitches, deficiencies, frustrations, and several things are not yet implemented (Silicoids, Klackons, a new faction and custom races are not yet implemented, for instance -- nor are a couple victory types including Scientific not yet implemented). The map camera has that annoying 'bounce to event' ala Civilization IV. The AI is pretty stupid, of course -- Brad's blogging about the game development process reinforced something I already guessed at -- AI has to be the last thing to put a real effort into in a game development, because it has to interface with game systems; those other game systems have to be working first in a finished state before one should bother trying to get an AI to use them smartly. Don't expect the Early Access to be challenging versus the AI.
One /nice/ feature that the game has is you can save your game even while the turn is being processed -- very handy given the Early Access nature as I've had a couple end turn processing that's stuck. Also on turn processing ... it tends to be quick. I'm not sure if the developers copied Stardock's idea of having the AI do most of its crunching figuring out what to do /while/ the human player is taking their turn, but I have a system that's aging a bit (FX-4130 w/Radeon HD 6570 which I think is a couple generations old at this point, made before DX11 I think), end turns process decently fast -- but I might be biased in relative assessment there, as Civ V really frustrates me how it can take a minute or more for a turn to process late game on a large map on my system. :/
If you're kinda on the fence, I encourage you to check out some of the Let's Plays being done by several casters to get a sense of the look (I know there's always a difference between watching and playing). I think my favorite thus far is Quill18. Here's a link to his Master of Orion playlist thus far: https://www.youtube.com/playlist?list=PLs3acGYgI1-urU9zxp4B02cZwBdIGs8Qu
You can buy it on Steam for $50 which includes the original MOO1, MOO2 and MOO3 (which I think many of us already have/had, myself included!) or I think you can also buy it on GOG.