I love cave story but cs+ plays better and has many more creature comforts than the original. I'd never encourage someone to buy it over the original, but at the low price of free, vs. an already free game it's hard to say "play the original." You're right that the original dev got fucked over by Nicalis but my understanding for free games on services like this is the devs get a big lump sum from epic or Amazon or whoever else is distributing them and they move on. In that case, they already have their payday so why not just take advantage of that to play one of the most important indie games ever made with like. Remappable controls and actual 60fpa (the original ran at 50 lol)