Really fun game, and the only one so far to me to make great use of the lives mechanic.
I've seen debates online about how lives are from a bygone era and don't hold up to todays games.
I understand how they were in older games, but games nowadays are quite balanced, challenging, and fair. The lives system is moreso to me an inconvinience, since all that happens is that you're sent back to the beginning of the level (which oftentimes aren't even that long to begin with).
But this game solves that by being insanely hard, and sometimes straight up unfair. There are segments in this game which you NEED some lives to spare. It works nice in Story Mode but works amazingly in arcade, which sends you back to the start of the game if you run out, and even rewards you with extra points if you make it with a bunch. It let's this game still have that old-school, arcade feel, while bringing it into the modern age.
There's other things I love:
The fact your combo is based around damage dealt instead of number of hits, so slower characters aren't invalidated.
The SPECIAL MOVES mechanic where it replaces your health with a green health bar, and getting hit destroys it and leaves you with little health. It encourages players to not get to aggressive with the games powerful specials.
The really fun characters with distinct move sets and combos.
This game is just really fun and engrossing.

When I was little, I remember loving this game and wanted to come back to it again, but we lost it.
Cut to a few years later, while I was playing on the gamecube, my dad approaches me and tells me to go downstairs, drink a lot of tea, use the bathroom and come back.
When I booted it up, that spinning coin in the loading screen looked oddly familiar, then was blown away when it zoomed in to the man himself, in his glorious castle, and hearing the triumphant music and those great words:
"WELCOME, TO WARIO WORLD!!!"
Then, the entire day blew by like that.