Not all of it. I dropped it and it cracked near the top middle, a spiderweb looking crack, and a few long thin ones branching out from there.
Now the top half of the screen isn't responsive.
What can I do?
You probably damaged the digitizer. You'll need to replace the glasstop.
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Yeah the screen colors didn't warp or anything like that
How much does it cost to replace the glass-top and where/how would I go about doing that?
Here's one off of eBay: US HP Touchpad Touch Pad Digitizer Front Panel Lens Screen Parts Repair Fix | eBay
This is the closest I can find on how to take out the digitizer. It only goes up to the frame, but there shouldn't be too much more to do after that. Installing HP TouchPad Front Panel - Page 2 - iFixit
Only top half? Lucky. You should have no trouble putting it into Developer Mode and making a back-up using webOS QuickInstal, in case something goes wrong when you open it up to replace the screen.