We are investigating how non-programmers make sense and solve simple computational problems. We developed a game where a robot has to assemble a sandwich, collecting a specific list of ingredients. Our game follows principles and offers game mechanics typical of games for learning programming. The main innovation of our game is that it visualizes the generality property of algorithms through double levels, that we call twin-worlds, in which one same algorithm is executed by two robots in assembling their sandwiches. Results from early testing with university students enrolled in the education of Media Studies show that the game is usable, levels can be solved at various degrees of complexity (e.g. with and without using loops), and that the students were able to make sense of our twin-worlds levels and formulate general algorithms for both worlds. However, the gathered feedback also highlights the need to explore alternative implementations of the twin-worlds concept.