You alone can't put it into the collection. You need to encourage others to submit it to a collection.

Voters can choose to click on "Recommend for a collection!" under the "Help this artist:" heading. Then, they tick the boxes that they think apply to the flash animation/game. If it gets enough recommendations, then it goes into the collection.

What I suggest you do is to make a new blog post, and link everyone to the flash, asking if they could put it into the collection. I don't really like emo stuff, but I'll recommend it for you, to give you a head start. :)