It's fun in and of it self, but lacking organisation such as a mini map or certain map restrictions to unlock later thus giving the game a sens of progress or "flow".

Just my opinion tho.

Start collecting gems, realize that I'm reviving some evil demon god, collect all of them anyways. Walk past the beam of light, climb back up on my own.

Heh. The arrows at the beginning count as living things. You can kill them and collect their souls.

Endings:
* Saintly McDwarfsaint: Climb back up under your own power. Do not collect any gems and do not kill anything. Collect the Fruit of Youth on the way up. Your people will show you respect and the malevolent god is defeated.
* Unsung Hero: Same as above, but do not pick up the Fruit of Youth. Your people will continue to be the same jerkasses they were at the beginning of the game. Ironic because the game hints that eating the fruit is a morality choice ("But do you really want it?"). The defeat of the god is unchanged.
* Nice Going, Dumbass: Collect all of the gems. It doesn't matter how you get up after, the god is revived and gives you a free lift home, only to kill you (screen blacks out) after you find the sword. Your people act snarky about your screwup, even though they'll probably die too.
* The Dark Side: Kill 10 or more (I killed 34) creatures with Force Lightning and get the teleport spell from the Emperor (Dark One). It says up+z but it's actually up+x. You appear on a platform floating high above your home where another sith lord is hanging out for some reason. Your people are terrified of you. You get to kill the god like in the good ending, but he gives a self-righteous speech before dying ("You haven't killed the evil under the mountain, you have become it"). I killed the Dark One after getting the spell, I don't know if this dialogue was affected by that.

Things that might cause other endings:
* collect some gems, climb up on own
* kill fewer than 10 creatures
* only kill the Dark One, climb up on own
* kill 10 creatures but do not kill Dark One

Saintly McSaintdwarf ending if you just kill one creature (the Dark One in this playthrough).