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.

Okay, I tried to give it a chance. It is certainly very charming and is interesting for its time. But I grinded for hours and still couldn't walk through the map without being slapped by the monsters. You grind a lot, money is very difficult to get, since you need to grind even more. After the first couple of hours, it gets more interesting because you can finally go a little bit further away from the starting spot but then came the worst thing after grinding: you only save in the starting spot, so if your a long way from it and needs to stop playing, you're screwed. And then we realize that the items are very cryptic to find, and it is difficult to know where to go and the items are too expensive...
Yes, the game has a lot of problems, even though it's quite charming. I wouldn't recommend it, it's not worth the time it wants us to spend on 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.