You already know from other articles in this blog that I don’t recommend learning word lists. I believe it’s better to learn new words while you’re using them. However, learning a couple of words in a game can be relaxing and fun.
Click this link for some intriguing word games on Dictionary.com.
Another website you could try is Test Your Vocabulary where you can estimates how many English words you know. If you get to native level, you will know a cool 20,000, or maybe 35,000 English words!