Is is possible for me to play the game on the web? Because I don't have a gameboy.

No, this has to be played on a GameBoy. If you don't have one you can use an Emulator like BGB (https://bgb.bircd.org/#downloads) or Gambatte (https://github.com/pokemon-speedrunning/gambatte-speedrun/releases) to load the ROM provided.

Not sure which version are you looking to play on Web as this game is only for GameBoy however if you are looking for Wordle in German language then try WordleDeutsch.com