Academy Island is a nice educational game developed by Cambridge ESOL.
The main character is an alien who is on an island and has to go through quite a few challenges in order to graduate from the academy. The island consists of a few towns: noun town, pronoun town, etc and each town has 2-3 shops and/or buildings which the alien has to enter in order to complete his challenge and gain a high enough score to be allowed to get into the academy building. In each shop and building the alein is asked to complete 4 sentences or answer 4 questions: these are all multiple choice. Questions cover grammar, vocabulary, phrasal verbs and idioms. Correct answers bring from 100 to 150 points. The level of difficulty is shown in the top right-hand corner of the screen.
The 4-question set is timed. The alien has 30 seconds to answer the questions in each building. If he runs out of time before he manages to answer all the questions, the session is terminated and the alien finds himself outside that building. However, he can go back into the building, but the questions will be different.
There are also some scrolls with 2 questions in each. Correct answers to these give 250 points. In the building of the academy the alien is asked to complete the final challenge, which is to complete a famous quote. If the correct answer is given, the alien can graduate from the academy. If not, then he has to re-enter the building of the academy in order to get a new question.
A fun game that I am sure all English Language learners will enjoy. They can submit their scores and compete with their peers.