I agree with you that, taking everything into account, it's a good offer. It does fulfill the promise of delivering an authentic dungeon crawler experience, including character progression, grid-based movement, range attacks, and enemy variety (but no gear nor consumables) with only one card and a set of dice. This is a feat of design that I find worth praising.
Still, you quickly feel these constraints. The core loop becomes soon repetitive, and even though each level is associated with a different kind of enemy (well, the enemy repeats itself every four levels), the experience doesn't change much over the game.
Also, the retail version doesn't include the save pad of the KS version, so you end up with a box with nothing but a cardboard card and a few dice - for 10€, that is, more than games like Sprawlopolis and the like, it feels a bit expensive. Despite the small size, I would say the box is still two-thirds air.
If you compare it with another portable game like Deck box Dungeons, I'd say Deck box Dungeons is more engaging (but it requires either an app or the cumbersome printing of quests), but the footprint is way bigger. I have backed Dark Tomb recently which belongs to the same family of "miniature crawlers", and I hope it will be more interesting.
Stimpy! Did you already play the game? If yes, how do you like it?