Another new version of Criticality (two in a week!), this time I have added attrition mode. I've created this based on gameplay mentioned in a question on the stack exchange gaming beta.
In this mode, exploding pebbles do not capture neighbouring pebbles instead when they move onto an enemy space they eliminate themselves and one of the enemy pebbles. So far, my experience suggests that this can make for a very long games, i.e. it quickly becomes a war of attrition.