Just a note for anybody wondering why the scores and times don't match. Ebon_Heart explained to me that both the best time and the highest score you achieve is saved under your name. So, my fastest time was 3:30 with a score of 9000+. However, I played again, collecting all the gems and achieved the 12000+ score. That took me over 20 minutes.
I am wondering how people got past the top challenge. The 50M Creeper bars with the block in the middle. I had one idea in mind when I created that but later on I found a ridiculously easy way to beat it... So, feel free to add a comment here on how you beat that or any other challenge. I might put up a walkthrough in a few days if I get feedback that it's too hard to get all the gems.

Well, I just flew a blaster into the middle and killed the little block of creeper.. After looking at the fields in the editor though (I didn't do this when getting my score) it looks to me like you could actually get the creeper to overflow with the level 4 directional fields if you shoot a repulsor at it..
EDIT: Nevermind, the directional fields are anti-creeper only. For that matter, if you use a repulsor at it I have absolutely no clue why it does what it does, some (a relatively small amount) of the creeper mysteriously just vanishes, and the creeper does not explode from the pin fields as would be expected, unless you have the repulsors pointing in a direction other than to the right.
EDIT AGAIN: Ok, so the creeper was being moved over to the right (and on the bottom side one of the normally 100 density blocks had a lot of creeper shoved into it which I didn't notice before, so there was no creeper disappearing), as for why the creeper doesn't explode, I'm not quite sure still - apparently if there's a repulsor/directional field pointing into a pin field the creeper only moves in parallel/opposite directions as the directional field within the pin field area (didn't know that before), and for some reason or another the repulsor (only when facing to the right) reacts strangely with the level 4 directional fields at the left edge of the bars, and prevents the creeper from moving to the left - if you have the repulsor pointing to the left the creeper will have no trouble exploding..