You are Iron Fröst and you must to activate all the bombs and reach up the next level avoiding guards who try to catch you.
You can freeze blocks into floor near your location to temporarily trap guards and may safety walk atop them.
Also breaking frozen blocks you can reach some bombs.
Over time, frozen blocks will regenerate.
A trapped guard who cannot escape immediately respawning at the top of the level.
Floor may also contain trap doors, through which men will fall, and solid blocks, which you cannot freeze.
The faster you go the better, because over time your score is reduced and for zeroing begin to explode these bombs that you have activated.
If you was dropped down, or if you stayed in regenerated block, or activated bomb exploded - bonus will be reduced.