I didn't get all the way to the end since my save has already reset multiple times after accidentally clicking anything that refreshes the page, and loading my save did nothing except make the whole game unplayable, but here's my final rating:

Fun: Not very fun. Game is very slow and doesn't speed up with more prestiges. You also don't know when the next prestige is gonna show up, which is a problem especially when it's such an integral part of the game, and creates a sense of confusion. Getting eras doesn't really feel like you're progressing because the only thing that changes is the name. Regardless, the game has done an okay job of making all the buildings stay prevalent.

Uniqueness: I like the premise of eras as a sort of prestige/level mechanic. I would give it higher if eras did more than unlock new upgrades (Which were already shown to you anyway). There was time now also features a similar system where "eras" unlocked new resources but unfortunately they felt too independent. Maybe a system where eras unlock new resources and sciences which give boosts to production.

Theme: Again. The only real prevalence to time is the eras mechanic and the names of the buildings (which don't really affect production). 

Additional feedback: 
Display for net currency gain/gold gain per sec would be nice, along with a display that says reach <x> gold (or is it currency? I have no idea) to reach the next era. Hide the upgrades before you reach them so there's a real sense of progression through each era. 
Add displays so that people know what a "human" and a "machine" is.

Bit boring with how the prestige just gives the ability to buy upgrades with nothing tangible boon, but outside of the repetition it's fun enough

There isn't much going on here, since the prestige mechanic doesn't speed up or evolve the game, beyond opening up some upgrades (though they're just increasing some numbers). It would have been nice to see something change with each era, beyond the text.

I didn't play all the way to the end, since I accidentally reloaded the page, and it looks like the save system isn't working.

It's also possible to soft-lock the game by buying too many gold upgrades. The first resource goes into the negative and doesn't recover. Bugs are a fact of life in game jams, though!

So to be perfectly blunt, I was initially put off by the looks of the game - the basic thumbnail, the default Unity buttons, the slightly blurry default Unity text (I’d recommend switching to TextMesh Pro), and a generally uninspired interface with a lot of dead space, and a couple issues with text going outside its containers. Sorry, I know this is a bit harsh but first impressions make a big difference so its important to get it right.

That all said, I do really like the whole premise of eras being levels, and progressing through them. I think this could be a pretty strong game, if the interface is improved. In addition to what I said above, some QoL features could go a long way - how much currency am I making per second? What goal do I have to hit to move to the next era? etc.

The balancing also isn’t perfect. It’s a bit slow (especially since the goal for each era is unknown), and the beginning of each era is identical, which gets stale.