Scattered throughout the World Wide Web (which, I remind you, is not the same thing as “the internet”) is a wealth of game information, although as old sites die out increasing this info is really hosted on the Wayback Machine. I previously presented the Bubble Bobble Info Pages, which are among my favorite game sites of all.
A relatively recent addition is this description of the great nuance in Capcom’s 1991 fantasy brawler Knights of the Round by Sebastian Mihai. It should be remembered that at that time Street Fighter II was already out and making it harder for games that weren’t one-on-one fighters to succeed. Capcom had a lot of experience with belt scrollers at that time, having made Final Fight and Dynasty Wars by then. A few years after they’d make the (IMO) even better Dungeons & Dragons brawlers Tower of Doom and Shadow Over Mystara, which I think are probably the pinnacle of the genre.
As just one example of the thought that went into Knights of the Round, most of the pickups in the game can be struck with your character’s weapon, and this splits them up into multiple smaller treasures, that are both usually worth slightly more than the original, and if desired can be shared with other players. It’s the only brawler I know of that does this!
Last year hackaday reported on Sebastian’s project to create a improved version of the game by hacking the game’s roms. The project page for it is interesting reading for people of a technical frame of mind, going into detail of the hacking process.