I think there's not enough places to get spades, and way too many where you loose them. 100% loss at each level with embers and at each chest of the smallest type (you get a pick axe instead), not to mention you can loose them on levels where you don't recover your tool. You can only get an extra very rarely in bigger chests. So this limits playability of certain routes - you cannot simply go on a route when there's too many places where you are sure to loose your only few left spades. In comparison, you only loose a pickaxe 100% on levels with keys, and you can get on extra on those with embers and oil, and quite often in chests of all sizes.

But if you don't have spades you can't collect anything if you move forward (including the pickaxes). In general, I feel there shouldn't be types of levels where you 100% loose a spade - because with only a few spades in total (I'm up to 7 atm, but it takes more than 24 hours for all of them to renew, so I usually start with 5-6) it doesn't make sense to do them at all. Very often I loose 1 or 2 in the first few levels just because the box is not there (don't know why, but most of the time the first level I do has no box with a tool). With 3-4 left I will not try to open a mini chest or go for the embers - otherwise I can complete maybe 15 levels in total (30-40 min of gameplay) and then it's hours until I can play again. So maybe change that at least?