Just uploaded v1.0.2 which adds a Retry option when you fail to complete a level 🙂
Nice, just finished it! Retry helps indeed :-) Like it even better now :-)
That last level was huge! Perhaps what might help here btw is some sort of map or indicators that indicate either where the items are or at least which part of the map you covered. I know, are more advanced feature and a bit of searching around never hurts, but just an idea that popped up.