Hey !
The idea is simple ! :)
But we had little time to put it all together, that's why it might be a bit confusing !
On the first part, you are in a shooter arcade gam, where some weird forms (that happens to be letters) are spawning. When you destroy them, you "collect" their form.
Once you think, you have enough of these forms, you can press Esc to get into the pause menu and with the signs you collected (they appear as a number and a form in the puzzle part), you can fill the letters in the puzzle. If you fill enough of it, you'll get a score based on your time to collect the forms (and in theory based on the forms used be we did not had enough time for this :( )
If you can't fill the puzzle up, than you can go back to the shooter but you'll get a penality!
The goal is just to clear the level / have the greatest score (But the score is not perfectly implemented yet)