Race mode is amazing. The AI is already godly at roping.. you'll probably want to add a dumber one for noobs. AFAIK there has NEVER been an AI that can rope before - very impressive. The game handled my .png map flawlessly, and the start/end position and turntime counting features are wonderful. Love the ghost and zoom features. Still getting used to the physics but they are pretty intuitive - glad you reversed the upside-down extend direction.
For long races, I recommend adding the ability to create checkpoints
You could add a "practice" mode/checkbox where if the frog drowns during a race, he gets teleported back to the last checkpoint. (Similar to WA's "antisink")
After a race ends where the player successfully reaches the finish line, it might be good to ask "do you want to share this map and your ghost online for others? I certify that I own the required copyrights etc". Then we could race against other people's ghosts, have things like a leaderboard, daily featured map challenge, etc, even if nobody else is online. Asking after the game would help ensure map quality, correct start/end/checkpoint placements, and overall playable/bug-free.
It's really incredible what you've accomplished in such a seemingly short time.. keep up the great work!