Fixed!

I love it! It's a great level! The gameplay is just so good. :)

Oh nvm you're referring to that completely useless thing of 3 colored blocks on the side of the thing with the portal, idk why I made that, and I probably will make it so you can return

@Mrs Ellie "You might want to make a way to return from the portal pillar (that blue ledge just looks so enticing, but there seems to be no return"
What do you mean?
Also, based on the comments, it's apparently not not very good like I said in the description

I found it! :) Boy that was hard to get to!

under the start

Where did you find that??

http://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=634759860

I totally agree with Limboh - you have really captured the essence of good gameplay, which is making the player think and encouraging them to be creative. The level is only big enough to get the job done, and the player has the minimum necessary blocks to accomplish their goals.

You might want to make a way to return from the portal pillar (that blue ledge just looks so enticing, but there seems to be no return - maybe a possible area for a secret?
I thought I saw a platform under everything as I fell to my death, so I was searching for a secret somewhere.
You might consider placing a blue cube downstairs and using it somehow to get the last red cube . It would increase the gameplay a little.
Very, very well done! :) What a pleasure to see lean, effective gameplay!

Great level, I liked everything about it from design to difficulty.
The lack of checkpoints made the last jump really intense, which a lot of people are not going to like but I am a fan of danger.
Very creative use of the collapsing door.
Great choice of music.

A little bit more decoration on top would have made this level perfect.