Submitted a T228 victory, but I had all the pieces for a ~T215 win: Atomic Theory T200, 5 AIs eliminated T203. Didn't know what to expect so I played it pretty safe and delayed PP to turn 154.
I've had AIs build Great Library before T40 in a couple of test starts, so I chose to skip that entirely and go for units instead, then built ToA, HG and NC. Sent my early archers to nearby barb camps and collected a bunch of CS quests, got some maritime and militaristic allies. Later on these militaristic CSs will provide me Keshiks and Impis, but at first I get a bunch of useless catapults.
I had 3 AIs on my continent, killed one with archers, but then I couldn't really do much against the next two AIs. So after a pretty uneventful war vs the remaining neighbours, I had to run my units back to upgrade to CBs and have a couple of them linger within my borders for their XB upgrades. This was all post-Education; a smarter game plan would've been to research Construction and upgrade immediately after the first war, clear the continent, upgrade to XBs and cross the ocean.
Another OCC annoyance is that AIs can't offer you their cities in peace deals, so if they think they're losing a war badly, they won't offer you anything at all. You can still sell stuff in peace deals, but bullying the AIs of all their money and luxuries won't really work.
Science was the easy part. In my game I didn't have any jungle tiles, got two natural GEs (first one due to the early ToA and HG and skipped GL, second one in the end when I wasn't paying attention) and only one faith GS, and still got all the required techs before I was done killing AIs. I think you can finish both conquest and research by T190ish, so a narrow sub-200 or at least a low-200s victory should be possible.
T228 is likely beatable with a peaceful approach given a good enough start, but if you're aiming for a really fast game I think you have to go warlike.
