>>46301367The gacha thing is a completely optional and very minor feature that has you put various items into a machine and give you an item depending on what was put in. There’s definitely some guides on what you can potentially get from it.
That thing aside, both areas are basically huge Wild Areas with a bunch of landmarks and different biomes. Isle of Armor has a beach, ocean with small islands, a forest, caves, an upgradable Dojo, and the Towers of Water and Darkness. Crown Tundra is mostly tundra, grasslands and graveyard, but there’s the Regi temples, a small village, the giant tree with the Galarian Kanto birds, and the cave for the Max Raid Battles.
The dojo has a “Restricted Sparring” mode that’s basically a monotype Battle Tower. On the other hand, Max Raid Battles let you team up with up to 3 friends to take on a series of Dynamax Pokémon and a legendary or Ultra Beast at the end, but you must use random rental Pokémon every time (you can swap out rented mons with ones you catch before the end). Shiny rates are really good though and you can keep one of the caught Pokémon of your choice at the very end.