Thanks for the feedback!
I totally agree about the lack of clarity, and the fact that it just drops you in without any sort of advance warning certainly doesn't help.
I did have the thought early on that making games best-of-X (and having some resource carry over between rounds, probably?) would help make a full match feel more substantial. I'm still interested in keeping each round within the 10 second time limit (it really forces the game to cut out the fat, focus on interaction) but it's hard to get into a good flow when it all ends so abruptly.