I like 1, it has that gritty rugged early Genesis feel. A lot of those Genesis games that came out from 1988 to 1991 were like that, before the SNES and Sonic's success pushed the Genesis in a more colorful and more lighthearted direction. 2 is great of course. And 3 is way better than it gets credit for, the addition of the roll and the specials gauge are real improvements. There's just the one level with the rails that goes on for way too long, and the samurai boss is annoying. Other than that, very solid. SOR4 is cool but it's not a real SOR.
--The original arcade Final Fight is great if you're in the zone because it keeps you so busy with all the enemies. The ports don't do it justice, and the SNES sequels suck (especially 2, terrible game).
I was thinking that the Genesis having more colours after '91 was mostly because more people understood the hardware and used its full colour palette.
But I get what you mean, Altered Beast, Golden Axe, Gain Ground and almost every other "pre-Sonic" game on the console felt much more "mature" and serious visually speaking.
But I'd argue it was also a bit of the case on the SNES comparing a game from '91 with one from '94 - '95. Consoles tend to have better graphics over time (well, until the last two gens sadly).
The Special Gauge is really a life saver and makes you do more special attacks with a good timing instead of that weird "health regens a bit if you kill an enemy with your attack but it does not always work".
The underground railway level was a neat idea on paper but agreed, it was a bit too long. The Samurai was a nice reference to Shinobi but having three times the same boss is just bad (even worse in the US version where each ones have three full health bar).
Why isn't SoR 4 a "real" Sor?
I haven't played 2 nor 3 so I cannot tell but Final Fight One on the GBA is a decent port imo.
I never did beat any of the original 3, but the 4th one I was actually able to beat. Semi curious to see what Sega is doing with the new title in the series
I have never finished SoR 1 in solo without save states, two players make it much easier despite the double amount of bosses.
SoR 2 was the first one I managed to finish without any help but it was because Max is quite overpowered as a brickhouse.
SoR 3 is just made to give kids a hard time... Bare Knuckles 3 is much more feasible but the path for the best ending is still challenging.