thank you so much for playing! and yeah, the game gets pretty hard from level 7. level 9 is the hardest level in the whole game (in my opinion, at least). there are a total of 11 levels in the entire game (excluding the tutorial) and only one true ending (or more of an unsatisfactory "to be continued" ending 'cause this is a demo after all), so you just have to get all the way to the end. it could take 10 to 30 minutes if you start from the beginning.
also, dang. didn't think anyone would find that secret. what happens here is the g̸a̴m̶e̵ ̸f̸r̸e̴a̷k̶s̵ ̷o̵u̵t̴ ̶w̴h̵e̵n̸ y̴͕͌ǫ̸̎u̴̙̤̇́ ̸̪̊͜g̵̲͔͊ơ̷͔̤ ̵̯͕̂̃ő̶̰̼u̷̢̅t̵̟̜̂͑ ̷̙́ọ̵̑̄f̴͈̱͆ ̷̹̌b̴̜̂o̶̢̦̚u̴͎͋̀n̵͍̚͝d̶̲̮̿͑a̵̲͋ṙ̶̉͜i̷͇͕͐̕e̷̒̊͜s̶̤͆ ̵̝́ă̵̛̬n̷͚̓d̴̤̕ ̴̙̭̿s̵̤̈́̾t̶̳̃a̶̗̅ŗ̸̈́͊t̴̟̂̾s̴̯̭̍̑ ̸̪̈́ḽ̸̯̀ô̸͖ạ̷̼̉̈́d̴̨͛i̸͉͙̊n̶͙̆͂g̴͙̑͐ ̶̧̣̓i̴̘̙̕n̶͉̝͌̀v̴̛̭̪̋á̸̧l̴̨̰̽̏i̸̯̰͌̓d̷̫̼̍ ̵͚͎͗̍t̵̝͆̀i̴͖̋͑l̷̠̩̑ẹ̴̀̿ ̶̠̹̑̆d̵̗͈͂̕a̶̢̩͠t̷̥̅̕à̴͈͝ ̵͖̥̂͝ḟ̵̡̑r̴̢̹̿o̴̗͑̉m̷͙̞̆̆ Ṟ̴̺̜̽̿̅̚͜Ǎ̴͉͈͇̈͆͊̾Ṃ̴̤̟̓̇ ̴̢̛̹͈̰͌̒̾͜͝e̷̜̓͗v̸͖͔͍͋ͅe̷̺̤͗̊̂̎n̷̳͆͗̈́̆ͅ ̸̈́̓̈́́ͅṯ̸̡̔̏̾̈̂h̵̩̯̬̟͐͛̂̂ō̵̭̠͕͇̚͝ù̸̡͓̗͚̤g̸̬͉̤̼̃͛̀͋̈́h̴̳̝̯̅̉͑̋̊ ̴̲̖̑̏̉̀͝t̸͈̊͊̋͊̿h̷̡̛͎̟̻̑̿͝ȁ̶̪̿t̷͖̹͈̉͑̃̍ͅ ̴̖̈́̓̆͠m̵̧͉̣̙̀e̵͓̠̖͔̱͗̈́͂ȧ̶͈͙̞̮̎̈́ṇ̸͕́s̷̭͒͐̚