I recently started playing you game, and I must say, it's fun!
I've been having troubles with floods and lava floods though . Often when I'm busy drawing arrows, some huge flood is spreading... It would be nice if there was a sound that played when lava/water got loose. The sound would be larger as the lava/water spread.
I've notice some little visual things as well, when you have lava pouring into a hole from 2 or more sides, it looks odd.
Also, dwarves that dig into lava sometimes seem to survive for half a second and keep digging, this also looks odd.
This game is fun and addicting, keep up the good work.