Systems that focus on Companions

Looking for inspiration for a game I am trying to work on. As is, I'm shooting toward a Videogame. But before you can develop (without a bunch of Revision and Balance) you need a solid concept, and some kinda playtest. So I may try to get a couple friends together to help make it into a tabletop and mess around with ideas. Surely I don't need to tell you, Some of the Best TTRPG's make equally great VG's. The Also has been done in vice versa.

My main 2 focuses on the game is

1. To make it simple to learn, but very expansive. Spanning Sci Fi and Fantasy.

The first thing that pops into my head is Rifts, which I am very aware of. Deffinitly looking more into that. But outside of Robots, I am having difficulty finding what I am looking for. Which leads me to....

2. Companions. The other main focus is to have a companion to reflect/enhance your skills or broaden them where your character can't.

So far I have 3 major options besides the obvious other 2 options (Going solo or with another pc/npc)

-Robots: Ranging from little utility droids, to Mech-Armor

-Spirits: From familiars and critters, to Dead rockstars. Even Gods

-Creatures: Think Pokemon, but you also fight. Also passive creatures for farming or utilities