Game development benefits from short iterations, because it is often concerned with how a game will feel like; something that is hard to anticipate. Live programming aims at reducing the length of iterations during software development to allow for faster exploration and improve program comprehension. Mainstream game engines such as Unity or the Unreal Engine already support some aspects of live programming, however, only for very specific use cases such as shader programming.

To support a more general live programming workflow in game development tools, we propose a live game development environment. The environment supports developers in two aspects: how will a code change affect the look and feel of the game and how does the behavior of the game relate its code? The proof-of-concept environment ensures short feedback cycles by always keeping the game running while it is being developed. We propose several mechanisms to work with the running game, for example, when working on code, programmers can automatically replay situations in the game that are relevant to the change by using an explicit notion of snapshots. We tentatively demonstrate the effectiveness of the live programming features in the context of the development of three game prototypes of different genres.