These are good decisions, but then the strategy will be something like this - I grind N ghosts, then I go to fight. If nothing worked and the ghosts died, then I start grinding again. Even if the optimal number of ghosts is small with a large number of attempts, grinding will still make up the bulk of the gameplay.
As for me, the optimal solution is to make the number of lives, after which the player dies completely. Until he lives, enemies will not regenerate.
In any case, I liked the game and left a good rating.