I finally reached my goal and I now have 50 playable levels!

These new levels include new features (Spoiler):

• pre-merged dudes at the beginning of the levels
• up to 2 controllable dudes at the beginning of the level
• background change to sunset color from level 25
• improvement of main menu
• build Standalone version (in case browser is not suitable)

Next scheduled:

• better music
• various animation improvements
• more levels