No, you're not.
The technical goal of the game is to gather the four fragments of the holy artifact, which will transport you to a hidden room where you defeat the final boss (the one's handling the trial, AKA probably the player) by invoking the artifact.
The whole game is a bet between the Light and Dark Gods, who set up a trial of sorts for their paragon followers in the labyrinth. Each of them sent a representative, with said representative being the final boss for each heroine.
The real goal of the game, naturally, is to gather all the CGs for a heroine (by advancing down the H-scene/Monster Tech Tree). Getting combos help you regenerate MP faster and maintain the heroine in an 'undressed'/armor break state (that said, heroines are permanently armor broken once they get the breast 'upgrade'). You'll also want to drain your heroine's faith to the red region (in addition to completing the tech tree for the respective heroine) before confronting the final boss if you want to get another H-scene.
Excessive comboing can completely drain the heroine's faith, which is an automatic lose condition (faith basically functions as HP). This usually happens when you stack too many catapult traps [unplaceble, but present naturally in maps] in one trap combo.
You also lose if the turn counter reaches 9999.
