I've been experimenting with this deck too (because I got saddled with GRNDL as my ID for a random ID tournament...).
I've played against variety of IDs, including Sunny, Noise, Valencia, Kate, and Leela.
I've had wins when my opponent did something crazy and floated tags gambling I wouldn't have a Scorched Earth.
Other than that, I've lost every game. It has a number of problems:
1) The SEA-Scorched Earth threat isn't real early game, as there's only one SEA Source in the deck and it's hard to score an overadvanced Atlas early while maintaining a money advantage. Runners can and will run wild and free early on, and statistically this strategy will win them more games than it loses.
2) Power Shutdown has done almost nothing - I have used it more for pushing through an Indexing/R&D lock by trashing my top cards, rather than trashing programs/Clone Chips. There is plenty of cheap stuff being installed, and runners have tons of recursion. Smart Shapers won't run with an SMC out until you install-advance, or if they do run they will pop SMC for a breaker.
3) Archer isn't good any more. Even if you can land one, the loss of the agenda point delays you by at least a turn and usually 2-3.
4) Blackmail wrecks you. Valencia (and even weird Noise decks doing strange bad pub things) will crush you.
5) Faust wrecks you. The kill is the only hope you have against these decks, and between Imp, I've Had Worse, Plascrete, money races and only one SEA Source in the deck, you have no hope.
In short, it doesn't threaten the kill very well and it needs a way of winning that isn't reliant on the runner not having the right breaker or doing something stupid (e.g. getting dragged into kill range by a Snare!). It's worth making direct comparisons to Butcher's Shop here, because both decks are the same idea. But Butcher Shop's kill flexibility (through Plascrete, forcing runs due to Breaking News, no need for a full combo all at once thanks to Midseasons, assets helping the money race, no bad pub) is far superior, and the scoring potential (Astro, bluffed as naked assets, overadvanced Beale) also far superior. This plays into spiky, porous ice (Pop Up, Gutenburg, Data Raven) leaving GRNDL struggling with its mess of end the run and impotent program trashing.
All that said, it's maybe the best GRNDL deck around. Casting Call might give it a lot more teeth than Snare!, as it can let you score against a broke Valencia even with Blackmail.