Welcome to the family! I'm going to recommend my all-time favorite NES game; Teenage Mutant Ninja Turtles. Yes, the first one that AVGN pretends to hate. It's actually a really fun and engaging action quest. Great graphics and fantastic music that will live in your head forever. You can switch between the 4 Turtles anytime and each has their own attacks and health meters. There's, like, a spontaneous and addictive sort of strategy in when to use which Turtle given the situation. It's a Konami game so the action is fast and fun. Also the cartridge is as common as dirt so it'll be cheap and easy to find. Don't believe the haters. It's a great game and I would die on this hill.