There's one that I use for level 4, when I'm playing for fun, rather than farming. I've never tried it out farming anything, but I don't imagine it'd do much good beyond Silver.
I call it "Malignancy Is A Virtue".
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Fairly straight forward - Aflatoxin your own Photons, heal yourself with Bonds, have your Shard out until you've got enough oomph to kill the opposition, then kill them. You can also use Aflatoxin on opposing creatures, and Skull Shield will protect you from the resulting Cells but, as a general rule of thumb, only do this after you've infected one of your own creatures. The healing from the Bonds will almost always be better than destroying 1 enemy creature.
I've not collected any data on it, but it seems to win most of the time. Weaknesses, obviously, are Permanent Control and Gravity Shield.