Thanks !
I definitely agree with you ! The game sorely lacks background music and tutorial levels (and a control guide).
It's just a shame we didn't have the time to add any of it.
As for what the structures do... Tbh, they do nothing at this point... We only had time to implement the summoning tiles : 1, 2 & 3.
The four-tress (see what I did there ;) ) was supposed to block ennemy movement, and the 6-temple was supposed to heal/ressurect units.
It just was too ambitious a scope for such a short jam.