Serious games are viable alternatives for learning and for acquiring new skills. Serious games introduce users with a learning environment that mimics real life situations, where they can practice and improve their skills. While considering education, we focus on games used for language learning, which cover multiple categories that range from vocabulary acquisition, comprehension, collaboration, to free text writing. The serious game described in this paper -the Astronaut Game -is design for English as Second Level users and consists of two parts. The first part consists of a Platform Jumper for vocabulary acquisition, in which an astronaut runs and jumps to collect rocket pieces that symbolize words; the aim of this sub-game is to teach words from different lexical fields to the players, depending on the level they are playing. The second part, the Rocket Hangman, is centered on comprehension and users must identify the central keywords from the reference text. Our game was tested by a group of 16 individuals and received positive feedback.