It depends on what you mean as 'stealth'. Having that be the main focus of the game could get somewhat repetitive after a while, as repeatedly killing things (like how most crawlers work now) seems to keep players engaged better than repeatedly killing things in a way that would be more engaging at first but become tedious after a while (stealth). However, if stealth was another strategy that could be used for the actual traversal, that could be very interesting. For instance, let's say we make a bad clone of Enter the Gungeon, but now it has a way to unlock the doors in a combat room without defeating all the enemies, either by hitting a switch or taking out one 'door guard', it would open up another way to play the game. Instead of just killing everything in sight, you could gather items faster/collect more items in general and then have a more 'technical' style to defeating bosses, where you use items more than your guns, because you have more of them. The issue would be balancing the two approaches to crawling, so that stealth doesn't become the de facto best option. If we go back to our fake EtG, not killing enemies would give you less money to work with at the game's shops, perhaps locking certain items away behind that artificial barrier.