Though Wario starts out only being able to charge attack to break cracked blocks & jump normally, throughout the game he collects treasures that unlock new abilities, somewhat like Metroid.
Hold Down while in the air to smash down toward the ground, breaking any cracked blocks or weak enemies below you. Stuns strong enemies.
Yes, Wario needs a special item to be able to swim. Just use the control pad when in water to move around under the surface. Pressing B as you swim will allow you to swim a little faster.
Allows you to break blocks with your head by jumping under them. Also stuns enemies from below.
Allows you to pick-up weak (small) enemies by walking into them while stunned. You can then throw them to break throw blocks (or other blocks masquerading as scenery) with the B button. Holding the B button while holding an enemy will charge up and stronger shot, which will make them go farther—but watch out, because you can also accidentally kill an enemy by throwing them too hard at a wall.
A stronger charge that allows you to break solid blocks, as well as kill stronger enemies with only one hit.
A stronger ground pound that allows you to break solid blocks from above, kill stronger enemies in one hit, and creates an earthquake effect when hitting the ground, stunning any enemies on screen.
Allows you to jump higher by holding Up while jumping. You can jump even higher by jumping off of an enemy while holding Up.
Allows you to swim even faster by pressing B while swimming. You can swim so fast with this that you can go past currents.
Allows you to pick up stronger (large) enemies by walking into them while they’re stunned. Note that holding larger enemies will slow you down and weaken your jumps.