This is my project for C++ course. Some screenshots:

You need to blow up the planets by pushing them into black holes. Use arrows to move alien dude. Press "R" for restart level, press space to make the alien start to move randomly.
Firstly you need to install SFML library:
sudo apt-get install libsfml-dev
Then compile:
g++ run.cpp Game.cpp Map.cpp Cell.cpp -o run -lsfml-graphics -lsfml-window -lsfml-system
And run:
./run
Enjoy!