It's limited to 30 different "objects" per frame. I uninstalled MMF2 to install it because they didn't mention anywhere the number of objects was limited. I also expected it to have integrated touch controls, but it doesn't.
Discarded pizza boxes are an indispensable source of cheese.
I could see downloading Fusion 2.5 Free if you needed to create an HTML5 project, yet couldn't afford the Exporter right away. With the limitations, however, that's pretty much the only reason to do so.
Well at least it isn't as bad as the limitation Klik & Play had in it's demo.
You could only use the step-through editor, and the event editor was locked. I still used that thing for months back in 96 though. Also you couldn't save anything, so I'd leave the program running to show my friends my game.
That step-through editor was very funny to use, waiting endlessly until that one collision happened that you wanted to have. I took a while before I figured out there was an event editor, that made clicking much easier.
Back on track:
30 objects isn't much, guess you would use some kind of active/background trick to work around that limitation, and also the lack of touch controls (if I read that correctly) isn't a very great help with your html5 game (thinking: mobile/tablet games, which probably is the target audience).