Definitely a fun game! A few things I noticed however, in both the Windows version .09 and the html version:
1) On repeat playthroughs, if I purchase upgrades from the prize wall, the graphic for the upgraded water gun will carry over, as well as the blacked-out boxes of the upgrades I bought, but the increased water flow won't carry over, and I don't have the option to purchase the water gun upgrades a second time.
2) It seems like I only get one chance to take on the Boss Clown; they showed up on my first time reaching Round 3, but once it reset to Round 1 again, she didn't show up the second time I reached Round 3.
3) On the prize wall, I'm not able to buy the 300-ticket stack of water balloons, no matter how many tickets I actually have.
4) A very minor nitpick, but the target point on the fan dancer clown doesn't appear to be her mouth, but just above it, about where her nose is.