This week's game is Spelunker II: Yūsha e no Chōsen, one of two games called Spelunker II. This sequel takes on a light Metroidvania-style structure with combat and bosses, but it still has the Spelunker fundamentals we've all come to love:
I'm not sure why they decided to make two Spelunker sequels called "Spelunker II", but they're at least pretty different experiences. The arcade Spelunker II is a logical expansion on the original game, but this Famicom sequel made a lot of changes. This game is essentially a light metroidvania in the vein of something like that NES Rambo game or the NES version of Rygar - you've given a nonlinear world and asked to explore it in order to find what you need to get to the boss. It's done in the most simple way, only locking things behind keys and not abilities, but the exploration gives way to a much grander experience nonetheless.
Reviews of this game see it as a total departure, but I actually think it does a really good job of keeping the spirit of the original game. There's still plenty of platforming (and it's as terrifying as ever!), you still take damage from falling, several familiar hazards return alongside those ghosts, and caution is advised at all times. You become more powerful as you play, but you can never get comfortable because one death is all it takes to start the entire thing over. It's a game that doesn't quite have the same goofy, lovable, playfully sadistic vibe, but it understands its roots and simply seeks to incorporate them into a format that was perceived to be where gaming was going. It's certainly not a perfect experience nor is it one that people would consider particularly "polished", but it's one heck of an interesting example of how people were figuring out sequels at the time, and I think that's always a compelling thing to mess around with.