Hey thanks for playing and reporting the issue. I just tested it on my end but it seems like the Jackhammer is still functioning under normal circumstances. Can you perhaps provide me with more information? Perhaps there is some combination of items that causing confusion or a bug?
Here is me with the Jackhammer and you can see the bricks are 0 Power. BTW, it won't help with Mimic Bricks (11)!
Ah, this definitely could've been the case, since I was doing challenge runs! It was either that or an unexpected interaction. I tried recreating it in the base game mode (using cheats for money to get it & other items to test with) but I didn't have any issues.
It was definitely the base bricks, because I remember seeing health ticking down 1 at a time and going to reread the jackhammer to see if I'd missed something. I realise now that my original report was unhelpful because I forgot to actually document the case it was bugged in </3 Apologies for that!
For more helpful feedback: I've overall been adoring it, you took the Dragonsweeper formula and did a great job of expanding it! The only request I have is some sort of item description on the character select, so that I don't have to load into a run to see what items do.
