The web versions uses local storage for saving, which is independent of cookies so clearing cookies/not saving cookies normally shouldn't matter. However looking into this it appears that Safari throws a javascript error when using local storage in private mode. Are you using safari in private mode by any chance?
The Steam version automatically saves using Steams cloudsave functionality so it won't be a problem on that version.
No, I'm not in private (incognito?), only use that for other stuff... I've tried to test this, and it did remember my progress after just refreshing the site, but i think it was yesterday i tried that and today its forgotten the progress again. So it seems to happen over time. I'll try to see what happens in Chrome.
EDIT: I'm in chrome now and it seems i already quickly tested this last time, cause i started from the first checkpoint, so in that case it could look like safari is wiping the local storage after a while. Now I cleared first stage to test it so we'll see if chrome remembers that. Temporary conclusion: don't use safari for this game.
EDIT 2: Confirmed, Safari erases the data after a (very) short while, Chrome remembered most of the checkpoints in the stage, though i cleared the whole one. Firefox probably works the same way. Opera doesn't erase the data, but transforms it into a Trojan horse. Netscape asks for the floppy disk to save on. Internet Explorer crashed when opened.
