If you ever wondered what it would be like to use Spelunky 2's sublime platforming mechanics in a world that doesn't reset every time you die, a new mod called Spelunky: Wrath of Kali might just be for you.
Wrath of Kali is a massive mod that turns Spelunky 2 into a handcrafted Metroidvania. Instead of the world resetting and reconfiguring every time you die, there's a single, interconnected world to explore. If you die, you just respawn at a checkpoint, and can take on the same challenge all over again. The mod is not yet out in full, but there's a substantial demo for you to take for a spin, and it's extremely impressive.
The mod goes way beyond just being 'one big Spelunky 2 level,' too. You collect power-ups that let you return to previous areas and explore new paths. You can grab heart pieces to expand your life. There's a Souls-inspired potion system, where you can refill a limited number of healing flasks at checkpoints. It even opens with a classic Metroid ability teaser, letting you play for a bit at full power and then taking away all your toys and challenging you to find them all over again.
If you haven't previously modded Spelunky 2, it's a bit of a process, but nothing too complicated. You'll need to grab the Playlunky tool in order to install Wrath of Kali, and you can get both from spelunky.fyi. Just make sure to back up your saves before you do.
The best roguelikes should meet the best Metroidvania games more often.