Cave Story Tribute
Cave Story is a free indie game created and published in 2004 by Daisuke "Pixel" Amaya. You can download it here, or get the remaster on Steam for $15. There's also a Switch port for $30 (I think).
In my opinion, Cave Story is the greatest game ever made; every aspect about it is near-perfect. The gameplay and difficulty curve are fine-tuned to a molecular precision. The storytelling is masterful, and the soundtrack slaps. It's a masterpiece.
Before you read anymore, go play the game! Going in knowing as little as possible and using as few guides as possible will give you the best experience.
I myself am quite good at Cave Story. I beat the entire game, including the Sacred Grounds, without picking up any health upgrades. Not many others can say that. Here's a video of that: