Some gameplay if you have no idea what this is.
Um Jammer Lammy is a sequel to Parappa the Rapper set in the same universe but following a different character. Rather than being a rhythm game about rap, this one is mostly rock with some other genres mixed in.
I'm kind of shocked that despite playing Parappa 1 and seeing some of Parappa 2, I never heard of this one. This one was made in the middle, and despite the name making it sound like a spinoff, it is basically a direct sequel (Parappa is even in this one too).
This game is way better than Parappa 1. The input detection actually works here so you don't randomly lose when you're hitting buttons on the beat. The game's still hard though, just less unfair. The length is similar to the first game but you'd be surprised at how quick you can beat it now that the game works properly, it took me just under 2 hours.
There's a surprising amount of post-game content though, including a hard mode where you get to play as Parappa, and boy does it get insanely hard. People that 100% games are going to have a rough time with this one.
The only thing it doesn't have over the Parappa 1 is the music though. The music here is good but it's not as catchy as the first. The story is also a totally incomprehensible acid trip that I can't even explain if I wanted to. At one point she gets fat from eating pizza that the town thinks she's in labor and drags her into a hospital with a bunch of pregnant women. Yeah.
TL;DR: A great sequel to Parappa the Rapper that got completely overlooked for some reason, which is a shame because it's much better in many ways. Highly recommended if you're a rhythm game fan.
I did see the alternate stage 6 cutscene beforehand, but It's the first time I saw the other small differences! Rammy saying "OK... You win, I guess I'll just go back to hell now" on getting defeated is way funnier.