I did, yeah. Though I might have managed to barely scrape by if my browser didn't completely lock up at one point and stop accepting inputs while the game was still running. I was strongly considering calling it there after getting the other ending but luckily for me performance improved enough on the second try onwards that I could give it a fair share of attempts without going completely insane. Playing Sonic Spinball on the side while waiting for the game to reload the level might've helped, I admit. (Been playing for over a month and still haven't even gotten to the last board, that game is brutal.)
I think the difficulty is perfectly fine as is. Maybe having a minimap so you can preview what's up slightly ahead could ease up the memorization load so you wouldn't go "damn it, I forgot this was there!" right after using a box to speed up. But if you want to just say that having to memorize everything is a feature that's fine too. Just brainstorming. Up to you whether going back to this game is worth it or not at this point.
Pardon if I'm overextending myself by now, but since you seem fairly receptive to comments I'll take the risk of coming across as a bit nosy: at first I thought this was gonna be a more straightforward droneification-themed game, but given what went on with the full TF ending that doesn't seem to be the case (which I'm personally pretty content with since the whole latex drone thing is not really my cup of tea). It's a pretty intriguing image nonetheless, and got me asking plenty of questions. What did the goo actually do to him? Is it some sort of "devolved" life form/parasite/symbiote that needs a host to reach its final stage/something closer to its "original" form? What's it gonna get up to once it reaches civilization (more specifically, how does it spread once it has a host)? Why'd it need to go through all the trouble of encasing him completely in that shiny suit to do its thing? Why does it make him grow tits? Is that toy he's using on the incomplete TF ending made out of the goo or is the color just a coincidence? And most importantly, why'd he grow such a sizeable "endowment" after the goo made it almost non-existent? (were you ACTUALLY planning on doing a more straightforward drone thing before walking back on it?) Sorry if I'm being annoying. I know most of these are just varying degrees of "because it's hot" but if you have any more in-depth answers I'd love to know.