runouw.com

Sorry, I had to give this 2 stars for these reasons:
Most of the minigames are way too easy... I'll comment on each one of them:

Thwomp'in Burn'in: The player can just jump on the first thwomp, then glide to the exit. It's also unfair to start Mario directly under a thwomp.
Find the correct LEGO pipe: This is just a matter of picking the correct pipe/door. There's no clues at all and it's just guesses. You can use signs to make some puzzles/quizzes and that will make things more interesting. The wrong pipe/door doesn't take Mario anywhere, so all we need to do is enter the only other pipe/door and we win.
Lava Mountain: Again, it's just guesses. There's two pipes on either side, and only one works.
Frosty Lava: This one is rather bland, you can just hold right and Mario will get across the gaps.
Single Platform Balance: This doesn't help that I'm giving the level 2/5 stars. Like "Frosty Lava", you can just run across the gaps, and you probably need to do some testing, Mario sometimes can't stand on that pipe and touches the lava instead.
Spinning Object Strategy: It's just a room with a spinning platform, I don't see much "strategy" about it.
Hidden Block: Not a bad idea, although the "window maze" is nothing new actually, and it's too short.

And then there's two doors above that apparently leads to pointless rooms with nothing in them and I was mislead to believe there were more minigames.
One of them is a flame tower which was impossible to get past without getting damaged, and when you get to the other side there was nothing.
The other is just a corridor, and it looks like an incomplete room where more minigame doors were supposed to be.
I had no idea there were three more minigames at the bottom off the start of the level until I tried zooming out, you could've added a sign to tell the player about it.

Find the Walkable Trees: This one is a decent idea, but it's still too short.
Nameless minigame (Single Thwomp Finder): I got stuck between two Thwomps never to get out until I restart the level, you really need to test for such bugs. Also, there is a misplaced sign inside the wall, and I assume it's meant to be this minigame's name, this shows that you didn't properly test the level.
Boil the 2 High Power Bullies: Didn't you already have a bully fight earlier with "Lava Mountain"? This one isn't much of a difference.

I don't want to sound harsh, but it's just not that good. That's just the gameplay alone, graphically the "rooms" are obviously floating in the air, you can even see the "rooftop" under the first room when it's supposed to be higher.

Here are some advices: You could've used red coins or silver stars in each room to encourage the player to play every minigame before getting the shine sprite.
And honestly, since the majority of "minigames" are just common obstacles, it's a better idea to make an actual level with those obstacles. I see you have an "adventure" for Mario Minigames 3, maybe you can try that there.