NASA’s Astrobiology magazine has an awesome article entitled If We Had No Moon. You’ll already have worked out that we’d have no tides, but did you realise that if the Moon suddenly disappeared then it would dramatically destabilise the Earth’s axis? Or that all the animals that have evolved to see in moonlight would die?
It’s a common misconception that tides are caused only by the Moon, but without the Moon we WOULD still have tides, albeit smaller – the solar tide is about half the lunar tide, when in-phase we have spring tides when they reinforce, and when they act at right-angles we have neap tides. Without the Moon we would have only the Solar tides, about a third the range of the present Spring tides.