Ok, so neat concept, execution could take some work.

The good:

• It works! It's fun! It's like a cookie clicker - click the cookie, buy a cookie machine, a cookie factory, etc.
• Your score counter goes into E-notation! Your game didn't break because of success!

The bad:

• No clear success state. No change in gameplay after a certain point - the gameplay is exactly the same as at the beginning. The game just goes into e-notation and that's it.
• The shop doesn't react to my success. If I have a +250 bonus to that face of the die, I'm not going to care about upgrading my upgrade die so it does an additional +2 to the selected face. I'm just gonna keep rolling my main die. If I could buy +20, +50... etc upgrade die faces in the shop, that would be neat.
• You have lots of unused screen space everywhere. Put the tutorial on the side of the screen so that I don't have to remember the tutorial I read once at the beginning. Put a legend next to the shop so I know what all the things I can buy do. Put the explanation how to do the upgrade process next to the workshop.
• This may be personal taste, but all growth is linear. There never will be exponential growth to infinity because every cycle only adds. It would be cool if you could buy an upgrade that let you add a percentage of the last die roll to that face instead of a fixed amount every roll as is currently the case.
• I didn't have any sound whatsoever.

The Bug:

• Press A to go to the workshop, wait for the die blueprint/schema at the top to extend/fold out fully, go back to the game table. The game will pretend the die has been thrown to the same side you left it on. Just upgrade this one side ad infinitum and reap the rewards.

This is a cool game. It's a tad boring at the moment, and the absence of a success state is sad, but it works, it looks neat and it wouldn't take a lot to make it a great game.

EDIT: I had the idea that you could choose to pay more to roll the upgrade dice, with the result being multiplied. If you pay 1k instead of 20, the result is multiplied by 50 etc.

Thanks for participating and I hope we'll see you in the next jam as well!

Getting started was confusing. Not thrilled about a wall of text that I can't seem to access anymore once in game. Once I got an understanding of how to progress, it was fun. Seeing the score ramp up faster as faster as my die leveled up, getting more dice, levelling them up; the feedback loop creating by these interconnected gameplay loops was fun to figure out and run up that ramp. The glaring issue though, is that this loop doesn't seem to go anywhere other than back into itself. I'm racking up score, because it allows me to rack up more score, which allows me to rack up more score, ad infinitum. I played for a while after realizing this and can say that I had some fun just figuring it out and seeing how fast I can make it climb. There's just a certain let-down that comes with no other goal than farming a number higher.

Interesting concept to build your own dice! Though it is a little boring to just press the Space key to roll repeatedly. 

Even though I rolled enough to have all the upgrades, I could not get them to work on the dice at all. I could click to buy them in the shop, and the dice on the lower half reflected that something was changed, but I saw no real effect afterwards. In the workshop, I could not get the dice to change. The two die in the middle didn't seem to do anything, and no selection could be made to the dice itself. Clicking on some of the sides produced a different dice towards the top, but no interaction with that could be made. Sometimes clicking on other sides of the dice did nothing. 

I hope you can continue working on it, even with the polish jam that is happening after this one is finished, because upgrading your dice is a good concept that I'd like to see more of.