Introducing the Parasite

Formed parasite below me.  Unformed flying to my left.

The Parasite is a friend of spies.  It is attracted to the player and will cause damage when touched.  If the player isn't around, it looks for a Spy.  When it finds a formed Spy (one that has taken over a block), it will use it to stage its own forming and any block touching that Spy is available for the Parasite.  Once the Parasite has infected a block, the block can be destroyed but it will not drop anything useful.  The player will also receive damage to their drill bit.

I'm thinking that to remove a parasite or spy from a block, you're going to have to drop some water onto it to "clean" it.  That thought just came to me though.

Anyway, that's what I've been up to tonight.  Next on the list is a loading/saving progress bar.