I'm still able to play game using Newgrounds player. I'm also on Firefox browser if it matters, although of course not in incognito mode because most browser games won't save a game while incognito, I'm guessing that is perhaps because save info is saved maybe as cookies, and Incognito doesn't generally save them I think.
Anyways, yep, this is an awesome game, so far the only part that I'd suggest changing would be that often the Crystal buildings get selected accidentally when doing the click-drag thing when selecting multiple buildings, and i generally prefer not to send units from those buildings, as that slows the collecting of crystals. With the way that the game is set up though and how the controls function, I do not know if it would be possible to implement something that could easily fix that, and it is just a small issue that is easily worked around, i just personally feel that game-play would work smoother for myself and my style of playing is it were different so that only non-crystal (and maybe non-tower, etc.) buildings were selected when click-dragging, perhaps if it were possible to add a selection in "Options" where "non-normal" buildings were able to be toggled being selected by click-drag, or if they needed to be selected individually and dragging the cursor over them while click-dragging would pass over them... apologies over being so wordy for such a minor issue, I just wanted to explain it in a way that wasn't misunderstood at all.
Other than that (and contrary to the size of the text, it really is a very minor issue that i can easily work around), this game is pretty awesome and very easy for me to play for hours. The artwork fits very well and it all flows together with each separate part perfectly. I like the music, it's pretty cool and fits the overall theme excellent, although I would prefer a few additional tunes added, or at least variations on the main theme... a new part or different little instrumental piece added to the whole tune after each boss would be perfect. Again, not required, just would be bonus awesomeness! ^_^
Very great job!