Undertale Yellow is a fan made prequel to Toby Fox's Undertale where you take the perspective of Clover, the human possessing the Yellow soul of Justice.

To me, UTY nails the charm of Undertale so well, not perfectly, but incredibly well. It has such a loveable cast that're both funny and engaging, just like the original. My personal favourite character would have to be North Star/Starlo.

UTY's story focuses less on the meta aspects of Undertale and more on just telling a story set within the Undertale world, I know some folks won't like that since a large part of Undertale's story and identity was the meta aspects of the game, but considering Clover doesn't possess the same abilities as Frisk, it makes sense to me why the devs focused on just telling a well rounded story within the world.

Like Undertale, UTY features a Pacifist, Neutral and Genocide ending, all with corresponding final bosses. In the Pacifist route, you will finish the game by fighting Ceroba who attempts to take your soul so that she can use it to bring back her daughter. In the Neutral ending, you fight Flowey in a fight not too dissimilar to his Neutral fight in the original Undertale. In the Genocide ending, you face Martlet who transforms into her Zenith form after injecting herself with the serum extracted by her mentor, Chujin. I loved these bosses, my personal favourite is probably the new Flowey fight, but both Zenith Martlet and Ceroba are incredible fights too.

I've never seen a fan game so well received and loved that people talk about it and treat it in the same standard to the thing it's based on.