If you're looking for anime similar to Doraemon Movie 41: Nobita's Little Space War 2021, you might like these titles.
Doraemon and Director Burger try to set up a dramatic world where Nobita and his friends can truly become Space Heroes. However, the team soon finds out that Director Burger's scenario has come to life, and there is actual danger. Doraemon, Nobita and friends must work together to save Aaron and his home planet Pockle from space pirates.
The film is set on the moon and centers on strong friendships bound together by the "ability to believe." Luna is a mysterious girl who lives on the far side of the moon. Diabolo and his subordinate Goddard stand in the way of Nobita and his friends on their moon exploration journey.
After bragging about receiving a space trip ticket from his father, Suneo concedes they would have to wait quite a while until they can actually go. So, Nobita and co. turns to Doraemon for it, but they were given a space simulation game to play together instead. Unfortunately an accident with another gadget occurred, leaving Suneo and Giant trapped inside the game, only to be picked up by someone from outer space. Nobita, Shizuka and Doraemon then pursued the UFO that has the game inside it which took them all to a real space adventure.