I've spent about 20 minutes on it. Finished the Spanish questions and am now on my second run. Loving it! Great concept, even better implementation. Here are my thoughts:

1. The photos of the objects could be better, I would suggest designing them against a white background to maintain consistency and type, as some are drawn while others are photographs.

2. I have failed to locate a button to stop the "Keep Going" automatic count down. While its persistence makes me return to it even after switching tabs, some people may find that annoying. I would suggest A/B testing with no automatic countdown and with a "stop" button.

PS: The images of "El pez" and "la catarina" are broken :(