Am really tempted by Tri anyone played it?
Yes, get it. One of the most under-rated games from last year. It is a really, really good first person platform puzzler. It is very original, and the level design is superb. Highly recommended.
edit - copy-pasta from my review:
"Tri is a very very good game. It is a puzzle-exploration game. In each level there is a locked teleporter, which require three keys to open. Your task in each is the find the keys, find the teleporter and continue to the next level. Off course things do get complicated as you go along. To help you navigate the levels, you get the "Tri" - an artifact capable of producing triangle. The triangles can be created anywhere, as long as each corner is anchored somehow, and they are not too large. As you go along, the "Tri" can be used in more or less three ways - to create platforms, to be used to walk on walls and ceilings (dont ask...) and to bend light. The use of the "Tri" is fundamental to complete the levels.
There are in total 16 levels in the game, and if you know exactly where you are going and doing, some of them can be beaten in 10 min or so, though others require 20 min just to walk from start to exit through mazes. However, this is if you know the puzzles already, your first play through expect to spend 20-60 min on levels just to solve them. Added to this, there are an x number of idols hidden on each level, some of them very devious. These are not required to finish the game, but you unlock concept art and such by finding them. Finding all will take a lot of time searching and head-scratching.
The game in not "trippy" as such, it is in fact quite serene. The mood of the game is peaceful, and it is much more cerebral than twitchy. The puzzles are logical, and the physics are 'real', so do not expect any subversive puzzles like Antichamber. The game is highly recommend."