Nit: the tool-tips on the action icons in the top-right aren't consistent.

When music is playing the tool tip is "unmute" which is a verb. It should either be "mute" (to indicate what clicking will do) or "unmuted" (adjective) indicating the current state. Similarly, when the music is muted the tool-tip should either be "muted" or "unmute".

I'm not sure _which_ is wanted (verb or adjective) because the ruler tool-tip uses "Hide Ruler" and "Show Ruler" (verb), while the units tool-tip uses "Units: imperial" and "Units: Metric" (adjective). The info tool-tip ("Info") is also an adjective.

For consistency, I'd use a verb-phrase in all the tool tips:

- "Show info"

- "Switch units to metric/imperial"

- "Hide/show ruler"

- "Mute/unmute music"

I mean, I know this is pedantic nit-picking, but the site is so perfect, what else am I going to do?

Fun to see the Jerboa. I recently read a family history written by my uncle and he believes this is the source of our family name.

this has more of an indie gem feel compared to the blockbuster that was stimulation clicker. as others have mentioned it reminds me of scale of the universe flash animation. I think borrowing some ideas from that, including zooming in and out rather than side to side, could have benefits here.

EDIT: Nevermind. Perhaps it was an ad that I clicked on. Lots of comments here indicating they don't see it, and some that did.

My Original comment here (too late to delete):

Beware. When you reach the end there is a "more projects" button. In there is a cute IQ test (possibly appealing to the HN crowd). When you reach the end of the test it asks for email, and then ultimately wants $1 to get your results. If you pay by credit card due note that there is an auto-checked box for some $29.99 per month subscription for... something.

So wonderful. Thanks for making this so open. I'll show it to my kids. The artwork is very good and the soundtrack too.

It was great until Sea snail appeared in inches. Transitioning from micrometer/milliliter to inches is pretty rough

This is absolutely incredible. Thank you.

Minor thing that bothers me is that I can't scroll through the things like in the deep sea or space elevator.

So many loving comments, I have nothing more to add to them, and nothing to subtract from them.

Very beautiful. Love this.

If it helps, AFAIK (I do atomic force microscopy of DNA), DNA's height is closer to 2nm than 4.