It really doesn’t look different enough from the first one, I’ve watched a few runs, this is a mod pack or level pack, with very subtle changes and small additions. Dude made one game, sure it’s great, but he’s been making an entire career out of repackaging it slightly because the reviews go crazy for it.
Also, I checked on steam, the line the dev is using is “this is happening because you’re using an aftermarket hdd” which has to be utter nonsense, I’ve never heard of any PS4 game that has that issue.
Its not just "one dude" making a anymore. It hasn't been for some time.
Derek Yu created the original Spelunky in using the tool "GameMaker" and released it for free in 2008. That pixel art game he made by himself is quite different from what people now know as Spelunky.
http://gamemakerblog.com/2014/09/23/game-review-spelunky/
The game people recognize now as Spelunky is the 2012 HD remake of his original game. Released originally on XBLA. And then eventually on many other consoles. That Enhanced Edition / HD Remake had a team of people working on it. As does this new game Spelunky 2
Spelunky 2 is developed by Blitworks which was the studio in Barcelona that Sony introduced Derek to do the Playstation3 and PS Vita version ports of Spelunky HD. Derick worked with them by giving them design notes etc. But he admits he was mostly hands off as far as the art and coding of the game.
I played about 12 hours of the new game. It does have some of the same enemies and even bosses etc. But thats the same as all Mario games having koppas, mushrooms and bowser etc. The core movement and some familar enemies/characters are what grounds it as a Spelunky game.
There is more that enough that is brand new to make it feel like a whole new adventure. Especially the physics and fluid dynamics stuff with water or lava etc that can flow and pour and modify. That by itself is a huge game changer. But there is also the "back stage" areas of the map which is a huge change. Every level basically has doors to another hidden area behind it with secrets etc.
And I feel its well worth the $20 I spent on it.
Edit: been playing on PS4 pro. No issues with it so far.