Luckily they dubbed that game into many languages, including German, and the German versions were actually pretty awesome. The English versions in Rhythm Heaven were 'OK' at best. terrible (Dazzles, Fan Club), but they really improved a lot in Fever, I don't think any of the songs sound bad at all in english. The localization of most of the songs in Rhythm Heaven is just.
So if you've played the games, what do you think? And if not, go out and play them right now (you can always emulate Tengoku, and it's pretty intuitive so you can do it without knowing any Japanese)! And trust me, these games are pure evil at times (case-in-point: Moai Doo-Wop 2 on the DS one). I have completed the first two games, but I'm still working on Fever. Personally the DS one is my favorite, but I own all three (thanks to Pac for shipping me Tengoku). I didn't link any because I don't want to spoil them. There are also remixes which will suddenly switch between stages, set to a new song and often with cosmetic changes to make the stages fit the theme. In fact, the WarioWare team developed the games! I like to think of it as WarioWare meets a rhythm game. it's the same gameplay set to different songs? Well, in these games each song is its own stage with its own gameplay. You know how in, say, DDR, Guitar Hero, etc. If you're unfamiliar with it, these games are some pretty unique rhythm games. Sonikku introduced me to them, and I'm incredibly glad he did.