In content terms theres challenges to play against AI, plus matchmaking to challenge fellow humans
Whenever the player casts their second spell, they get a bonus
You need to do everything in one turn for Glimpse of Nature to be worth it, but in a deck with a bunch of small creatures, this can draw a ton of cards
What works in Bubble Mews favor is the combination of iconic artwork, Mews long-standing popularity, and its position as the defining chase card of the Scarlet & Violet era
This stage could be a completely separate blogpost, but let's note that he took the term "mana" from Larry Niven's Warlock books (and Larry had taken it from Polynesian Mythology, but was still rewarded by having his name backwards on neviN yrraL's Disk), and that he removed the use of dice and tearing up destroyed cards during this stage