This may be the first time I encounter a game like this. Well thought and I think also a fairly orginial idea.
The pixal art doesn't bother me, and snake control is quite fun to be honest.
However, unit movement is fairly bad.
The leader unit reacts just fine, but the follower units move like bricks. Only when the leader unit has moved away for a set distance does the followers move. This has caused more than one unnecessary casualty. I find myself swaying from side to side in a to large distance to collect everyone on a pile so that they are safe. If the follower units follow exactly the same path and move simulatiously with the leader unit, then I think the game would only be better. Especially on the 'Hellish Planet' level, bad follower unit movement has proven to be my down fall more than once.
That all aside, I think you did a very good job on this one!