One-Pass by LukeZaz 2017-05-14T17:00:15Z
First off I want to say I really like this idea! I think it has a lot of potential for an interesting action/puzzle hybrid sort of game.
I think this was already mentioned, but having some checkpoints would make it less frustrating when you're pretty far in and already know how to get this far. It was kind of fun to watch the area behind me get blocked off as I run, but suddenly it was pretty scary as I tried going in the other direction, since I had effectively just blocked myself in. And that was kind of a cool moment of discovery, realizing that my "power" was also my curse.
I couldn't quite tell how it decided which parts get blocked off, is it just whatever touches the circle, and then is no longer touching the circle? If so, it might be more precise if it were a square instead, so you could predict exactly which pieces would block off and use that to your advantage.
I'm eager to see how a more fleshed out version of this would look like!