Came back after a good while to see some pretty awesome updates! I'm excited to play through and explore the added content.
Found a pretty significant bug, though: If you click to metastasize, select a few upgrades, but then cancel metastasis, the malignancy is still spent but the upgrades remain unpurchased. It's super easy to go, "Oh, I can grab another (formerly locked) upgrade if I just had 200 more malignancy, better cancel," and then bam! An hour of progress lost.