The only thing I don't like is the time gimmick... which is the whole game is based upon. Having to finish the game many times just to get the different side-quests is a pain.

Rhythm Tengoku is a very fun game, with many cool ideas and aesthetic choices. The friendly looking minigames and the great soundtrack make us want to play more of it, and it is very funny seing the different outcome of our actions depending on our expertise.
As a person not very familiar with rhythm games, this one was the first I had contact with. The first set of games are somewhat easy to understand and to overcome, but it gets harder and harder, reaching a point that I can't get further in the game because of my lack of skill (and the language barrier, sometimes).
I like this game, but be warned that it is not as simple as it seems.

Pros: Nice graphics, with very colorful and detailed sprites
The soundtrack is just amazing
It is very fun

Cons: Sometimes it is too hard to understand and/or to be good at.

This game is very short, but very fun to a quick play, especially in multiplayer mode. The visuals are cool (albeit a bit bland), the movement is precise (albeit limited) and the game is kind of easy. Overall, it is worth playing.
Positive points
The visuals are cool and it has good controls. It is fun playing in multiplayer.
Negative points
The lack of depth to the gameplay and the length of the game.

I didn't like the Animal Crossing stages and characters that much, but the other tracks are very good. It passes.

It is very interesting looking, the Satellaview theme is very interesting and wacky, it looks like something Parodius would do ... but I'm really bad at shooters, only got to the fourth stage on easy mode.
The stages are very short, but there is a lot of things to avoid if you want to get to the boss.
I wouldn't recommend it to anyone that isn't into obscure Nintendo stuff as a hobby.

Why different skin of Peach and Mario? Why not new original characters? But okay, Link and the Hyrule course makes it worth it.

I have to say that, as far as homebrew goes, this game is incredibly good, which is more surprisingly is that it is a Nintendo 64 homebrew.
The puzzles, albeit kind of easy, are clever, and aren't too long. You can save anytime you want, and go back to any stage you'd like by selecting on the main menu. The duo mechanics are very integral to the game and necessary for the puzzle solving. I haven't played it in multiplayer yet, but it surely will be a very fun experience.
I recommend this game. It is short and fun. Of course you have to judge it by homebrew budget standards, but it becomes an incredible addition to the Nintendo 64 library.
If anything, some songs are kind of repetitive, and the graphics, too, but it is to be expected of the budget. Anyway, I'll give it a not perfect score because it could be more polished art wise (but it is already really good) and with more variety of scenery and puzzle mechanics.
I'd like to see a sequel for this one.

Not as good as the Tetris clone, but still enjoyable. It was very easy to lose due to bad enemy spawn, and that made me very anxious. The boss is pretty alright, but the loops repeat themselves over without much difference. It is okay.

It is like playing the original again, with new technology enabled and better controls.

A very basic concept, which doesn't allow for a whole lot of creativity. You spam the shooting button and that's it. The only strategy you need is to shoot the blocks which are closer, but it's only that. It is not very engaging.

1992

I tried to play, now that the English version is around... but it is still too damn difficult. The controls are laggy and we don't know exactly what we are doing.
It is very impressive technically speaking, but gameplay wise it should have been way better. It is like a glorified tech demo.

Review about the v3.0 (last stable release)
Good idea, horrible execution. It is a technically impressive ROM hack, with many custom abilities and characters, and it is cool to control them and their moves, but the level design (most notably, the enemy placement) is just a mess. Thematically, they didn't know what they were doing with each stage, which, by the way, drag a whole lot, having some states that took me up to 8 minutes to complete in a blind gameplay. The enemies hit you all of the time because there are too many of them, and they are in calculated locations to get you, breaking the "speed" of a Sonic game. The platforms and the scenery also want your doom, so you have to walk very slowly through the levels so you don't get hit or fall into a pit and die prematurely. This one is a very famous ROM hack, but I really struggle to understand why.