[SP] Antimatter One
Wow! It was unexpected to come back and see such nice words from the last few posters 
The map was pretty ambitious for me since i had about 3 weeks of hammer under my belt at the time, even for such a short map like this. Sadly since then i sorta drifted away from map making since the critism was often harsh 3: But if i get some spare time i might try and make a sequel to the map.
As for above poster, that was one of the many oversights i had in the design xD i had to guess anywhere the ball could land and make it explode the ball manually in that one room as the usual settings for making the ball explode are triggered by the lasers and i could see no way to prevent that/
Great job, loved the final room! The first two were no problem, but on the third one I spent a lot of time staring at it and saying "where do I start?" Eventually I figured it out and said "you want me to do what??" but it only took a few tries. It did take a lot of saving/reloading, and it was frustrating sometimes to be holding the ball and not be able to shoot any portals, but that just makes it a bit more challenging.
I made a video walkthrough for this Portal 2 Custom Map:
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I also uploaded another video, called sp_antimatter took FOREVER!: O1l0pvAq97E
Sorry to bump such an old map, but the map has been updated with 5 new levels towards to end
Did you rename the zip/rar/whatever before uploading ?
I'm still getting antimatter v4-1.rar from 20/5/2011
Five new levels? The file I downloaded only had three in it - unless it is supposed to continue after the elevator in room 3. For me it didn't open again after I stepped in and the doors closed.
Five new levels? I have only three. (and I still have 4.1 file)
As the map itself:
1st chamber: lol, easy
2nd chamber: Well, it is a bit difficult
3rd chamber: OH SH*T THIS JUMP IS IMPOSSIBLE
The concept of antimatter, an item that breaks upon contact with a surface is brilliant. Second chamber is a bit too difficult after the first one, though really well constructed. The third made my brain hurt, but once I found the solution I was incredibly happy with myself. Too bad I had to spend
Overall, the map is very difficult, but definitely worth playing.