Yep, it's the "Shoot Bubble" mode where bubbles keep falling onto the playfield one by one, and shooting them with the same-colored bubble makes them disappear. You can cycle through the colors. There are also some power-up bubbles that assist you during gameplay. You start with 5 lives in this mode. I thought this mode was endless at first, but the game does happen to end after 20 rounds are passed.
There are 24 views in 6 videos for Super Puzzle Bobble. About an hours worth of Super Puzzle Bobble videos were uploaded to his channel, less than 0.19% of the total video content that Dylan Sang has uploaded to YouTube.