Consume everything in the general vicinity
Well, judging by the intro-lines, we have enough mind to even notice our own existence, though much of it seems dominated by the need for nourishment.
As such, I actually would propose that we stretch ourself out in a thin film, wait for any positive responses (food), and then send more of our will towards that direction. But overall? +1
+1, maybe develop some sort of basic sound/vibration sensing capabilities
You use what energy you have to push your mass outwards, enveloping whatever unlucky creatures might be near. Your total lack of sensory organs doesn't make it easy to determine the results, but a sudden flow of vitality confirms that your "hunt" turned out rather well.
You are still hungry, of course. Hunger gnaws at your very soul. But it lessens. Just a little. Enough for you to think.
You push the new vitality into yourself, a little mournfully. You will hunger afterwards, you know. But feeling is necessary. It will help you to spread, to consume, maybe, someday, to cover the very world.
In little more than a moment, you can feel. You can tell it is not a perfect sense, that there is much room for improvement. But, imperfect as your senses are, they allow you to observe your surroundings.
You appear to be in a forest, dense with all kinds of vegetation. On the edges of your perception, you can feel the vibrations of bushes and shrubs, and the twitches of animals within them. Trees tower over the scene, groaning and creaking in the wind.
A particularly large pang of hunger tears you away. There will be time to observe your surroundings later. For now, it might be best to secure a steady supply of food.
The Corruption remains a crystalline blob, although it may have spread out a little. It has recently developed the capacity to detect vibrations.
It spreads just over a foot in every direction, and is little better than starving.
The Corruption appears to be in a sort of forest, although the vagueness of its vibration-sense makes it difficult to pick out details. More will become apparent with time.