Eeeeeh
Honestly I think Wario Land 4 is the only game in the series to deserve that title. It's where Wario platforming finally found a strong footing and identity in the action-puzzle genre. Prior games in the Wario Land series were heavily polarised on either classic platforming or Metroidvania without managing one or the other quite like the main reps of these genres, Super Mario and Castlevania/Metroid. I'm replaying Wario Land 2 currently and I'm surprised how mediocre of a Metroidvania it actually is, if it even tries to be one. Though, I will recognise that these games all nurtured interesting mechanics and incredible promise that eventually bloomed into Wario Land 4 and later shone with April sun in Wario Land The Shake Dimension Pizza Tower.
WMoD was certainly ambitious--a Metroidvania in its own right with positively intricate levels that one should sink more than a decent amount of hours into. It also marked the first time we've seen an actual story in a Wario platformer and an extremely fitting one for the character at that; also, let's not forget the great soundtrack. The game unfortunately fell short with the aforementioned truckload of minigames (the game was apparently trying to shove in WarioWare mechanics down to having a bomb-like timer), somewhat shoddy presentation, and, perhaps the most infamous of all, the controls: the touchscreen is shoehorned into much of your activity with this game, to such an extent that jumping is rather uncomfortably assigned to the same side of the console where the walking buttons are since your right hand is too busy handling the stylus. And what do you use the touchscreen for? To draw certain shapes on Wario so you turn him into different power-up forms. That function could have been relegated to a button press and a drop down menu without having an eccentric gimmick interfere with your enjoyment.
I guess much of what makes WMoD a bad game lies in the same flaws that plagued other DS games from around that time; that is, trying desperately to make use of the system's "new" and "innovative" technology (lmfao) for common gameplay mechanics in lieu of intuitive, classic actions such as a mere button press. The game is, however, quite substantial gameplay, design, and to a limit even story-wise and I'm sad to see it getting so much mistreatment. It ain't excellent by any means, but I've enjoyed my time with it and I could see that beneath those butt-begotten eccentricities lies work of talent and passion.
I do like WL4 more though.