You're correct. I'll try and recall what are the similarities with those 3 games. Been a while since I've played.
Across all three
- Shops
- House upgrades
- Fishing
- Crops
- Plant Trees
- Crafting
- Villagers relationship
- Selling
- Clothing
- Villagers quests
- Multiplayer
With Animal Crossing
- Tools break
- Museum
- Island Visitors
- Customise your island
- "3D"
With Stardew Valley
- Mines
- Ores
- Cooking
- Teleport
- Season crops
- Mobs
- Energy and health
- Raise animals
Dinkum only
- Vehicles
- Capture wildlife
- Metal detecting
- Gliders
There are probably more similarities but these are the ones off the top of my head.
Narrator: It was indeed nepotism.