Thanks so much! Was the biome you experienced somewhat tropical with the sea on your left and a beach to the right? In most of these past cases the problem was that the Itch.io client automatically downloaded an older becalm release rather than the latest one. This can be fixed by downloading the game from the itch.io website rather than the client, and selecting the Becalm_4_Windows.zip link option. That one should have all the biomes included, the main menu with timed and infinite mode, and the space bar functionality. Hope that helps :)
edit: corrected proper link name