Computer programming has become a basic skill and is now part of the curriculum taught in middle school. In France, this educational reform was very sudden and many teachers are not yet trained adequately to teach this subject , leaving them in search of guidelines and tools to help them. It is in this context that we propose TurtleTable, an educational game, who has two main originalities. First of all, this game is not based on writing a computer program, like most of the other tools, but rather on executing a given program, step by step. These two approaches are complementary and essential to apprehend the logic behind computer programming. Secondly, TurtleTable is played in groups of three, by manipulating Tangible objects on an Interactive Tabletop (TIT). The players have to collaboratively move the objects on a grid, by following the instructions of the program on the screen. The game immediately indicates which instructions are executed correctly, allowing the learners to correct their mistakes. TurtleTable was tested by 59 middle school students. We developed four different interactions for TurtleTable (TIT, tabletop, tablet and computer) to compare their effects on motivation, collaboration and learning. The preliminary analysis show that the students really appreciated the game, especially the TIT version, that encouraged collaboration and gave them the impression they learned more.