This turned out to be one of my favorites in the Jam so far, nice job!
The first time through I got my rear handed to me by the dragon, and I really wanted to try again. I feel you achieved the difficulty sweet spot, where an entertaining challenge and an initial failure inspire persistence. My second time through I defeated him, and it felt satisfying. The timer mechanic really made the adventure a rush too.
One technical critique: my first time through, I was *positive* I could enter the water at the dock, and that I could fire the ballista, but no matter where I clicked nothing happened. My second time through I realized that I had to click myself once I was in position to get the prompt. I seems much more common that the player is expected to click the object they wish to interact with, rather standing near it and clicking their toon. Once I figured that out everything worked great.
Another small one is that although I enjoyed your music selections, the shifts when key events happened were very abrupt, so it felt a bit jarring as the music stopped cold, then another tune kicked in. All that being said, the title track TRUCKS, and I knew I was in for a ride as soon as it kicked in ;)
The artwork was well done too!