I decided to check this stuff now because it would just be bugging me, lol!
Basically after Stage 16 it does indeed "end". Well, I mean it keeps going (Dunno if it has an actual end-end), but with the same layouts repeated with some slight tweaks. So I don't think I'll go further here because it's similar to Kirby's Return To Dream Land extra game in that it too played virtually the same despite the changes so I didn't do what would have been essentially replaying the game on camera.
Also, some Cart Run "practice"! ;)
-----
Time Stamps:
-Sub Games-
0:00 Block Attack Lv. 3 extras (AAA rank!)
9:12 Cart Run Lv. 3 (Fails, but has tips)
-----
Here are my other main accounts if you'd like to follow them:
PkGam presently has 22,647 views for Kirby: Canvas Curse across 36 videos, and about 9 hours worth of Kirby: Canvas Curse videos were uploaded to his channel. This makes up 1.08% of the content that PkGam has uploaded to YouTube.