I finished my game with 35 levels yesterday, but it took longer than I thought to design 15 more levels.
I designed quite a lot of levels on paper, but it was difficult to choose. I added some sound effects and tweaked some things which caused a lot of bugs in the newer levels, but I'm glad to inform everyone that I fixed everything. After two sleepless nights, I'm quite happy with what I made. If a lot of people like it, I was planning to add new levels and release it on Android and other platforms.
Please do play my game (and tell me which level was hard for you) and LINK YOUR GAMES in this chat, I will play them one by one and give you my feedback :)