For an early metroidvania, this is a pretty decent game. Definitely better than Metroid and Castlevania. For me personally, it did get a bit stale the more I played, especially when I had to backtrack, but for what it is the world is well-designed and was fun to explore. The controls also feel good, the upgrades are cool, and I especially love the boss designs. It's no wonder why they used one of them as the centerpiece for the box art. The sprites are massive compared to your character and that allowed them to be much more detailed, making them look very grotesque and menacing. Furthermore, the variety in gameplay is very nice. Having half the game be a side view in your car exploring the overworld, then going into a dungeon area where it turns into an overhead perspective adds a lot of diversity to spice things up. Overall I think it could use some work, but for an NES game, it's fun nonetheless. I'll definitely be checking out more games in this series as I'm sure they'll be even better.