MUST READ. PLEASE READ. I NEED HELP!!!!

You gotta use a ground pound to deal damage, it usually 4 or 5 blows even with this. There is no other way to do damage to them

Actually, that is how you unlock both worlds. In order to give damage to the bosses, as Mini Mario, you have to ground pound them by jumping up above them and pressing down on the D-pad. That is why the worm pops up really low every once in a while. Hope I helped.

I'm sorry, but only getting World 4 and World 7 is by beating the boss as Mini Mario. Just dodge, then strike with an opening. It's seems hard, but it's really easy. Hope this helps you out.

Well, apparently I'm not allowed to tell you the answer, due to you saying that you don't want to hear the real answer (defeating the World 2 and 5 bosses as Mini Mario). That being said, here is my suggestion: give the game to someone who CAN do that.

I gotta say, I face palm at not only the question, but to the answers. Clearly he is unable to beat said bosses as mini mario. That's fine, there is another way. What you need to do is stop off at a red mushroom and try your luck at getting a mini mushroom (or of course, as mini mario get another mini mushroom) as a second item. When you defeat the bosses as whatever you please, select said mini mushroom before grabbing the guy and presto, victory. It's the method I used before figuring out how to defeat the bosses with mini mario.

You have to ground pound as mini mario to do damage

First, you MUST get a mini mushroom. There's no way to beat it without one in W-2. After that, you'll unlock world 4. When you get to the ghost house, I forget what to do, but you can check youtube.com or any kind of walkthrough for help. I do remember that you need a mini-mushroom. So the way to get it in storage, go to W1-4. Get the mini-mushroom near the small pipe. Complete the level as mini-mario. Repeat the level and as mini-mario, go there again to get the mini mushroom. So now you've got that in storage. Again I'm sorry I don't remember what exactly to do in the ghost house. The mini-mushroom has to be used for wall jumping somewhere. In other words, if you know the secret exit (red flag) to the ghost house, then you don't need to read any of this. After the secret exit, the warp cannon will be unlocked and it'll shoot you to w-7. I really hope this helped.

I've got a strategie that worked for me. 1.Get a mini mushroom down on the bottom screen. 2. Go to world 2 or 7 castle as fire mario or something. 3. Get up to the boss of your selection and start the battle. 4. Ground pound on the boss while your still fire or super either will do(if your fire mario DO NOT use fireballs). 5. After you've ground pounded the boss once use your mini mushroom and hit them again about twice I think then you should have unlocked the next world. Hope this helps.

Kill the bosses by jumping above them. While you're in the air, hit the down arrow to ground-pound them. You must do this 3 times to kill them. Or, get the Mini Mushroom in your power pocket. Jump on the boss normally 2 times. Then, use your Mini Mushroom, and do the last ground-pound. It will kill him.

For world 4, do a ground pound at the boss in world 2 three times.If you don't want to defeat the world 5 boss in mini mario, then get a cannon for world 7 in world 4.(You have to find a secret door in the ghost house in w4. You need a mini mushroom to preform this trick.)

Heres how to unlock em two ways either get the mini mushroom by the entrance and only way to do damage to enemys as mini is ground-pound then the world is unlocked or go to a toad house get a mini mushroom when defeated boss use the minimushroom and get the key