Fun enough game. Unpolished areas of the presentation were a bit distracting (namely how shiny everything is), but the energetic, Dreamcast soundtrack more then made up for that.
Phasing through the ground is a bit harder to look past, but I think I'd be more bothered by that if I had the desire to perfect this game when it comes to time trials and score. Plus it only happened a handful of times.
Coins and boss fights felt like it was more of an obligation then anything. Really only one (maybe two) bosses had both interesting designs that made great use of the movement systems. Coins on the other hand are used for a shop that has some very menial effects, to the point that I didn't buy a single thing once. It's honestly not too great to have a prominent collectable feel boring to collect.
Really your here to speedrun through the many stages on offer, utilizing the momentum of your dashes and slopes so that your yo-yo ride ability can achieve some ludicrous speeds to skip large sections of the level. The many options you have while airborne can also allow for some clever shortcuts, whether it's simply dashing then comboing with a mid-air swing to fly over several platforms, to figuring out how to use a yo-yo bounce plus wall jump to reach heights that almost seem unintentional.

For what it is, I recommend you take your time your first time through, since mastering the physics won't be a quick learning process. Plus don't go in expecting a platforming masterpiece, it really isn't going for something grand or exceptional. Just sit back and enjoy the show for what it is rather then what it isn't.