A simple but addictive game: freerice.com. Choose the correct meaning of a word from four options – if you get it right, the next word will be a bit more difficult; if you get it wrong, it will be easier. After a few questions, you will see your vocabulary level, which will always change according to your answers. You can also listen to the correct pronunciation of the words.
Apart from practising your English vocabulary, you can also play with other languages and subjects.