Can you lovely people help me find this game?

[synthsequence]

Hello everyone,

I've been racking my brain for the last 6 hours looking for an AGS game I played many years ago.
I'd say around 2007 or so, give or take a few years.
I went through the AGS Games list for an hour and a half, checking each game, but didn't manage to find it.
So I'm hoping someone on here might be able to give me a hand finding it! I'll try to be as thorough as I can.
Also, do let me know if I've put this in the wrong place, and apologies in advance if so!

It was a free game, not commercial. It had a horror/thriller vibe to it. Quite similar to Clock Tower.
It had full motion videos; I remember this vividly as I was really impressed seeing it at the time.
The opening cutscene involves a camera panning around a house, zooming in on a picture with two brothers.
It didn't have voice acting, and I'm fairly certain the music files were MIDIs, but I'm not 100% on that.
I also remember that you play as one of those brothers. The other one has been killed or disappeared, I can't remember.
I think the brother you don't play as has disappeared with clues leading to some kind of cult.

One distinctive thing I remember was the game's shortcut icon and a symbol in the game itself was of a sort of yellow peace sign. It was a hollow yellow circle with lines going through the middle. A good example is the Borderlands logo, but in yellow.

Storyline/setting wise, I remember the main menu being a forest at nighttime, (I think). I believe you walk through the forest and find a house. After exploring the house, you discover the lair of some sort of cult, which I assume has something to do with the aforementioned symbol. The lair is underground, lots of dark brown caves, and I believe at one point you disguise yourself as a cult member. In the underground lair there are these teepee-like buildings that the cult members inhabit, except they're made out of what looks like stone.

Finally, while I can't remember the name of the game, I believe it was one or two words long. "Para" something sticks out in my mind, but I may be completely off here.

I never completed the game. I'm going on a massive nostalgia trip right now, playing Yahtzee's Days and 1213 series again for the first time since they were released.
It would really mean a lot to me if someone could tell me what it is. I would be forever grateful!
Thanks in advance for any help guys

[Crimson Wizard]

Definitely "Prodigal":
http://www.adventuregamestudio.co.uk/site/games/game/644/