Princess Tomato in the Salad Kingdom
Not many adventure games on the NES, and this is a good place to start for beginners. Nowhere near as punishing as similar games like Uninvited and Deja Vu. You can get stuck, and may need a guide here and there for some of the quirkier solutions, but you can't get outright killed and the game is more or less violence free. There are also no situations where you can run into an unwinnable scenario.
Apart from exploring and interacting with various screens and characters, you will also explore mazes, collect currency and "fight" in a mini-game where the goal is to predict where the opponent is about to look, and avoid the same prediction from your enemy.
You'll need to become familiar with the various commands, of which there are over a dozen. At first glace "Check" and "Look" seem like two words for the same action, but serve completely different purposes. You can also attempt to hit everything and everyone you come in contact with.
I hope you can enjoy this gem in the rough as much as I have.