Ah yea, the other green circle is actually left over from when I was making the levels and I made myself a mini "tileset" for placing stuff and then forgot to delete it on most of the levels. I definitely need to remove it when I get the chance.
As for your suggestions though they're definitely interesting, especially allowing you to hit a red dot to get smaller, I feel like that could go a bit more puzzle wise which would be cool. I actually originally had a few areas where you needed to be smaller to access them, but the way you got smaller at that point was to "drop" dots and gain speed and lose weight. Which was just tied to a hotkey, unfortunately the dots seemed to bug out with each other and I couldn't really figure out a way to balance out the mechanic so I ended up removing/disabling it.
On the topic of speed it seems quite a few people felt it was really fast, though I like your idea the best of what I've seen, adding a crouch/sprint to allow you to tweak your speed. The one thing I definitely wish I could've tested and tweaked some more is the slight acceleration I added to avoid you running into stuff so incredibly fast. I added a tiny bit, but then wasn't able to do as much playtesting as I wanted and it seems it wasn't enough :/
Edit: Just noticed you made Circuit Balace, that game was great! I think you already responded to my paragraph there so I appreciate a return paragraph here.