Preferably in 2 player mode because each and every one of those games are hard! Look at this shit, in most games you got at least a little platforming, very tricky jumps you gotta do to progress, every few inches of every level seems to be a death trap of some kind before you factor in the massive waves of enemies you fight while walking, fleeing, zig-zagging, jumping, climbing and falling down those extremely elaborate level designs. I'm not sure if I should even mention the bosses. I'd rather people play the games to see the bosses first hand if they never did before. They're some of the best bosses at least for character design.

I've played a lot of side-scrolling beat 'em ups. I think I might have been into Bad Dudes before Double Dragon, not quite sure but I know that was the other big beat 'em up around the time the first Double Dragon was popular and what I loved about both was that they were every bit as imaginative and intense as every other game in the genre for the era, but both seemed to be the most accessible. It's hard to describe why. Probably the controls being simple as hell, even by genre standards, and for me I think the pacing and variety in the action had a lot to do with it. Fighting is more fun when it's not all just fighting, and when the animations really "sell" the attack and reaction to moves, it's a lot more enjoyable to pull off those moves. Double Dragon, however, had much better, more over the top animations and character designs, and what you wound up with was something that stands out from the pack as much as Mario did from its competition at the time, but that would never be mistaken for cute, overly cartoony, and yet not too dark and cynical either.

I've been going through all my DD games, which is far from a complete collection, but I have the first 3 on NES, the first two on the Nintendo eShop if you count that the first is the Gameboy version, and as painful an experience as it is I have the 3rd on Genesis. I rented and played the shit out of the Genesis port of DD1 and can vouch for it being a stellar port. I'd say it might be a better port of its arcade counterpart than the Genesis version of Altered Beast was, and I still consider that an excellent port. DD2 on Gameboy I also have but often times forget it because it was a bit of a forgettable game, but it's not terrible and does kinda play like a DD game, just not DD2.

Controversial statement time: DD3 for NES is a worthy successor to and maybe something of an improvement over the NES version of DD2. It's underrated for being a massive overhaul of the arcade version if nothing else, turning that pile of crap into something playable and giving it a story that at least makes it feel like it belongs in the series. I'm not sure what the arcade version was trying to be except a cynical, blatant cash-grab in a time when DLC wasn't even a concept yet, because neither was the internet. But it sure as hell wasn't even a half-decent DD game.

But look at this shit!

It's like someone jammed Billy and Jimmy into a level from Mega Man and said okay now get through this with jump kicks and pure timing. The arcade version had nothing even close to a level like this, similar to how the NES version of 3 had way more useful characters and moves than the arcade original. However, 3 also doesn't have level layouts anywhere near this well thought out, unfortunately retaining it's arcade counterparts strictly left-to-right level design and progression, the size of the levels seeming like a lot of pointless, empty to space to literally jog through after you kill everyone who rushes you in the first screen of that part of the level, which is one big letdown. But, in this style of game, what's it really about, the level layouts or the moves and enemies?