Nice game! It did not load for me in Firefox, it only opened a new tab that loaded way too long (maybe I did not wait long enough, but a few minutes should be plenty of time), but the downloadable version worked.
I especially liked the music, but in my opinion the flat boat was a bit weird in the otherwise 3D environment, but that may just be due to time limitations, 3D models take time after all. I though it a bit unclear where the levels ended: In the first level the end was at the only watchtower, in the second level at the last one, with a clear path, but in the third level I had some issues: Right next to the U-turn, which is rather hidden, is a watchtower. In my first try I did not even see the turn and just thought: Here is a tower, this might be the end, and then I just ran ashore and took damage. Maybe communicate the end of the level better?
All in all, great, short game, with good and intuitive controls, and telling history nicely with great art and music. Might be the best I have seen so far.

I tried the game on Firefox and Chrome but it didn't start on my Mac.

Wow, we didn't know Harriet had a flying punt! But the takeoff animations were nice. good game overall
(((We did not find the 16K version of the punt, only the 720p one. We assumed it would be included, judging from the file size...)))