Enjoyed this! Something I noticed - movement was a bit uneven, until I passed through the portal and it was smoothed out. I like the zooming out after you die for a few seconds, which gave me enough info each time to keep progressing. Though I did send J.E.F.F. to his death perhaps a few times more than I should've!
We also made a game for the jam, would really appreciate it if you checked it out and gave us a rating :) https://itch.io/jam/gmtk-2019/rate/463422