I broke the game :(.
Lot a few times while learning the ropes,.. might be related but on my last death, i hit shield during the "dying" period.
Next game, when i hit shield, it stayed massive. my lives disappeared, but i carried on living. Killed the boss, did the portal, did the parents boss next, still are massive shield protecting me from dying (though hearts go down and shield time goes down).
So aside from that, nice game! Would have been nice for something more from the win portal, just to give a bit more player satisfaction.
I enjoyed the art and music choice to.
well done!