The best platformer games like Wario Land 4 are Pizza Tower, Antonblast and Wario Land: Shake It. Below are 9, each with the reason it is here — and, at the end, what filtering to platformer costs you.
Filtering to platformer means you want the movement itself to be the pleasure. It is the right filter when the thing you liked was getting from one place to another.
What you get: A game you can judge in ten seconds. Platformers live or die on the jump, and a good one feels right before anything else happens.
What made Wario Land 4 worth playing in the first place is covered on the full list. This page is the platformer part of that answer, and only the platformer part.
Openly built on this exact structure, and the best platformer of its year.
The other modern Wario Land homage, and very good at it.
The most beautiful entry, hand-animated throughout.
Where the transformation idea started.
Transformation as the core mechanic, in three dimensions.
Transformations used as platforming puzzles throughout.
The other Nintendo platformer that rewrites the genre's rules.
Transformation-driven 2D exploration.
If the timed escape runs were what got your heart going.
Weight. Platformers rarely carry a story you will think about afterwards, and the collectible-led ones can become checklists if you let them.
The full list is on games like Wario Land 4 — 9 picks, no genre filter.
Pizza Tower. Openly built on this exact structure, and the best platformer of its year.
No. Wario Land 4 released on the Game Boy Advance, but a recommendation is only useful if you can play it, so the picks above span platforms and eras. What they share is the genre and the reason.
Whether the move set is complete early. The great ones give you everything in the first level and spend the rest asking better questions of it; the weak ones drip-feed abilities to disguise thin level design.
Different games. 2D platformers are about precision on a single screen; 3D ones are about reading space and camera. Each pick below says which it is.
By hand. Each pick was written for the full Wario Land 4 list first, on what the game actually does, and this page is the part of that list that is platformer — never a genre tag lookup, which is how "best racing games like Super Mario 64" used to be a page on this site.
Or read the platformer guide for where to start in the genre generally.