Yes, the game is intended to be gone linearly
But I wanted to leave the possibility to see all levels in case you get stuck on one level I wanted you to still be able to see the others.
Maybe I should make it so that if you lose you keep most of your souls/bones so you don't have to repeat all of the levels.
During playtesting, we just farmed up on the first level since it has no towers.
Thank you for your feedback :)