First: Yes, this giveaway is indeed for Particulars (which sells for $14.99 USD), not Particula (which sells for $0.99 USD and was given away free).

Special Level 10 giveaway!

Please don't reply to this giveaway, please reply to the thread instead.

Particulars is a game with a unique combination of arcade-action and puzzle gameplay, set in the mysterious world of subatomic particles.
  
Taking control of a single quark, you must negotiate the fundamental forces of the universe. Other particles will push and pull at you - you'll always be on the brink of losing control and being dragged towards annihilation!
  
Woven through the game is the story of Alison, a young physicist struggling to outrun her troubled past. Her journey through the subatomic world is drenched in memories (both good and bad), and will ultimately lead her to some powerful revelations.

Overall: Mostly Positive (60 reviews, 71% positive)
Metacritic: 74/100

The winner will receive a Steam key for the game "Particulars" (not, as noted above, the similarly named and sometimes mixed up game, "Particula"), which will be manually entered after I've confirmed the winner. I'll try to get it up quickly, but please give me a day before worrying.

If you would like a second chance to win one of two keys for Particulars, please visit the thread for a Level 2+ giveaway!

If you know someone who is Level 10 who might appreciate a game with very positive user reviews, please tell them about my giveaway for The Night of the Rabbit!