SimplePlanes planet

Question: Is the SimplePlanes world round or flat? I know Earth is round, and I know that Droo and all of the other celestial bodies are round, but is the SimplePlanes world round? The reason why I'm asking is because I'm pretty sure that you aren't supposed to reach space in that game, and because they could simulate the game in a flat world if they wanted to.

i'm surprised too that one doesn't exist either
i could probably make it, but problem is that i don't have access to the heightmaps and the app i use to access outside-of-game features (including modifying orbit SMA's and importing images or textures so they actually show up in the selector in-game) no longer works normally with the game since 1.0+ :/