This time I will be counting best secret stages in Piano Tiles 2 - the ones which can be found in game files, but are not available to play - however, you can find a modded version of the game with secret stages.
6. Sonata Pathetique Mvt. 3 by Beethoven - this stage is not very long, it's not very hard, but it's a "true" Sonata Pathetique and it's really nice to hear that beautiful piece in the game. However, it should be a little bit longer :(
5. Murmuring Zelphyrs P.190 by Jensen - pretty fast, pretty difficult, and it sounds really nice. I don't know why, but it reminds me of "The music box" by Ed Poldini.
4. Katyusha (Russian Folk Music) - really hard stage, can be considered as a little bit harder version of Hungarian Dance no. 5 (because of the more double tiles and less holding tiles).
3. Gnomenreigen by Liszt - awesome surprise. When I started playing it, I was like "oh my God, another slow and boring piece, why do they make Liszt pieces so boring". And then - 23 double tiles in a row (not 24, I am wondering why). It was so cool when I expected 4, maybe 6 doubles, but they were just going, going, and going. In the end there is another streak of 23 double tiles.
2. Etude op. 10 no. 1 by Chopin - another surprise. Really slow piece, with almost only single tiles. I expected first star to show up at 100, maybe 150 points. But I had to wait for it to ~420 tiles. I thought "ok, maybe the first part is really long, but the next ones are probably very small, like in Horse Racing". But no, the length of this stage is 1255 pieces (one less than Turkish March). But there is one big disadvantage - this piece is really slow and repetitive, so it's really not-very-interesting to 3-star it and it's really painful when you fail at the very end.
1. Etude op. 740 no. 44 by Czerny - it's really sad that this stage is secret, because it could find a really high spot on my Top Hardest Stages list. It's surprisingly fast (I guess like 7, maybe 7.5 tiles per second) and it has no breaks. There are only single tiles going to ~680 points. Then you get only 3 long tiles for the end. It was really hard to get 3 crowns in it.