I just finished this Welsh point-and-click adventure game. You find yourself in a desolate farmhouse in Wales and get to investigate strange ghost-demon related activity there. Let's begin with the fact that it was fun at some times and some of the puzzles were enjoyable. Some moments of the story, too. On the other hand, many of the puzzles were very typical (find a light bulb to enter an unlit room etc.), some of the puzzles were randomly stupid. Many of the parts of the storyline are boring and they feel really random and illogical.
The game was made in 2008, but it feels like 1997. Graphics is OK at times, but most of the time it feels like a high school project, same goes with animation (but there isn't much of that). Music is almost non existant and when it's there, it feels like MIDI made by a single person over a weekend...
Rhiannon was made by a three person development team with Wintermute - freeware amateur software for creating point-and-click games. I got it in a game bundle, but I wouldn't recommend paying more than $1 for this game.
Also, there are bugs. Sometimes inventory items disappear. Sometimes menu buttons (MAP) disappear. If you save afterwards, you'll never get them back. It is a known and never corrected issue.
To sum up: if you ever played a point-and-click adventure game, you probably won't enjoy Rhiannon. If you haven't, you may enjoy it. I wouldn't recommend it though.