I’m a big cryptogram fan (Puzzle Baron’s got me addicted way back when), and I also feel like the public domain is an almost untapped resource, so I needed to try this and I’m glad I did.
I think I like light mode better (though it took me a while to find – settings and profile might make more sense to me combined into a single menu?) and I was a little confused by the Select a Theme page at first (I somehow expected solving one puzzle to take me to the next in that particular theme instead of back to the Select a Theme screen, and I also thought at first that it might be where you set light mode/dark mode, not poem theme, though that may have been me being more than usually inattentive ;) ), and I love the overlays. No performance issues for me! I also sort of wanted hitting backspace to take me back to the previous letter if I’d already erased the current letter, but otherwise the interface for solving the puzzles was intuitive.
Wild thought – it would be fun to have electronic adaptations of classical music for a soundtrack (I could even see different pieces appropriate to different themes, or a selection of pieces the user could choose from)!