I would like to register a formal complaint to the GM. Though it might stem more from my own misunderstanding of how each card works.
These cards have the same general board wipe effect. Except. One of them is significantly weaker than the other.
Storm cell has a delay and because of how it's worded, reducing max hearts rather than dealing damage, I think it would be fair to rule that if you don't die to storm cell you don't lose any hearts. Storm cell also cannot hurt face down cards, which the delay gives the enemy a chance to exploit. Why? Because it doesn't say that "All cards permanently have their max hearts reduced by four" but rather "Reduce the max health of all Face Up cards by four". Naglfar, which has similarly ambiguous wording around how long its effect lasts, only has said effect last a single turn. Both Naglfar and Storm Cell could feasibly have their effects be permanent, or in Naglfar's case last as long as the card is on the field, but instead Naglfar's effect only lasts for one turn.This means that, as far as I know, the reduction isn't permanent but rather temporary and perhaps even instant.
Unintentional bombardment is a 0 cost board wipe that will kill just about any 0 or even 1 or more star cost card on the field, with little to no chance to counter. Actions wise, it's a bit busted. You can't meaningfully counter it besides somehow keeping it out of their hand, keeping them from playing it, or setting up a card specifically to deal with it. Any counter to it is likely to have a star cost while it has none. It doesn't have the delay and all or nothing nature of Storm Cell, it doesn't have the randomness or cost of Meteor shower, it's a card that gets played and instantly wipes the board of pretty much everything.
This just feels Off to me. Especially since no cards shown besides Olden Plains Windmill and Pacifist Gun Waifu have enough health to survive the attack. Olden Plains Windmill is another thing I have a gripe with since it lacks the one feature it was built to have because tric couldn't decide on a numerical value for that feature and so left it out of the description and put it in metadata for the GM to decide. Which resulted in it being utterly useless outside of niche interactions.
I would like to explicitly state that I don't believe either of these are due to any malice from any parties. Just simple mistakes like everyone make sometimes. Or they could just be me seeing something where there isn't anything, in which case I would like an explanation for how exactly these two cards are equal.