The Hammer Bros. Suit is a second-tier powerup in which the character gains a Hammer Bros. or defense related power-up.
- Mario turns into Hammer Mario. He has the ability to throw hammers in an arc at enemies. The Hammer Bros Suit can also protect against projectiles and has some fire-based protection when ducking.
- Luigi will turn into Boomerang Luigi. He can throw boomerangs that travel along a set path until Luigi catches them or they fly off-screen. He also can duck under the shell for protection.
- Wario will turn into Sledge Wario, where he can create shockwaves whenever he lands from a ground pound, as well as throwing two hammers per button press. He also gains projectile protection when ducking.
- Sonic will gain the Kevlar Shield.
- Link will become Bomb Link. Link will throw bombs, just like hammers, but they will explode on contact with something. The bombs can destroy blocks too. If Link is ducking, then the bombs will move straight forward. Link's melee weapon changes to the Megaton Hammer in this form.
- Arthur will gain Golden Armor. This allows him to switch between weapons instantly and fire one while the other is still out.
- Samus will gain either her Varia suit, a full Missile set or a beam, picked at random.
- Roll will become Bass Roll. She gains multi-directional shots like Bass, but loses charged shots. Her basic shots do more damage however.
- Simon Belmont acquires his armor from Castlevania 2 and wields his Flame Whip.
| Standard | Super Mushroom | Fire Flower | Raccoon Leaf | Hammer Bros. Suit | Tanooki Suit | Blue Shell | |
| Crossover | Sci-Fi Suit | Mega Man Suit | Soldier Suit | |
| Other | 1-Up Mushroom | 3-Up Moon | Poison Mushroom | Starman | Lil Reaper | Stomp Boots | Life Energy | |