It wasn't bad. I got bored of it a bit quickly though, not sure why. I just remembered that Kirby game (Canvas Curse/Power Paintbrush) is also similar. Best Kirby game on the DS, better than Loco even imo.
It's a more guided line rider. You guide Kirby by using lines (you have a limit of how long your line can be). You can also tap enemies to freeze them, and you tap Kirby to spin and it's also how you absorb their abilities and use them. There's also bosses and actual levels. It's one of my favorite games on the DS. The first I bought for the system too.
The game was great, but had a too short main game. The medals and shitload of unlockables made up for it though, i'm still missing a few, i had about 97% complete. Deserves a sequel.