I think the answer to the fighting game question may be Chaos Code. Although it was made by a small Taiwanese team, they debuted straight in Japanese arcades so I don't think you would call it indie. Under Night In-Birth came out later than Chaos Code, but Eltnum previously existed in Melty Blood. All the other characters in the first UNIB are original though.
I saw Robert Axelrod at a convention around 2010 or so, he was a nice dude. I vividly remember him, already looking pretty frail at the time, saying "it was bullshit" that they turned Lord Zedd from a scary villain into a goofball after a few episodes, once parents complained about it being too scary.
Double Dragon absolutely did always play that horribly when you add a second player. Frankly, the frame rate is barely playable in single player half of the time. Even the second arcade game doesn’t do much better in that regard.
@goulash_enjoyer: Really this game has more in common with Natsume platformers like Shadow of the Ninja and Shatterhand than it does Ninja Gaiden. Those games just aren't as familiar to most, so they see ninjas and automatically assume it's a new take on Ninja Gaiden.
If, like Vinny and Ben said in this video, watching has made you actually interested in playing Rogue, I suggest you try the Shiren the Wanderer game that recently came out on Switch. It's a game that plays by a lot of Rogue's rules, but (at least for the main storyline dungeon) doesn't subject you to as many unidentified items that might have negative effects. Actual graphics might help you better analyze dangerous situations too! Oh, and it's on Steam too!
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