For a company that is iterating on its products this is probably fine from a mechanical sense but would be a nightmare for their IPs.
Consider the early Super Mario series:
- 1985 - Super Mario Bros
- 1986 - Super Mario Bros: The lost levels
- 1988 - Super Mario Bros 2
- 1988 - Super Mario Bros 3
- 1990 - Super Mario World
- 1996 - Super Mario 64
If in 1990/people could legally make their own “lost levels”-esque remixes with the SMB1 engine that would be paltry competition with SMW.
Similarly if people started remixing SMW in 1995 it wouldn’t have stopped SM64 from defining the 3d platformer genre and presenting a very strong argument for the analog stick being required for any 3d console.
But if people could tell their own Mario stories, that might tarnish the brand. If that happened we might not still be getting Mario games today.
I’m not sure how you open source both engine and assets without losing control of the narrative.
Yeah as far as gameplay mechanics go they would be fine, most main line Mario games have a unique gimmick.
I wonder if the family friendly branding would be as strong if people could publish rom hacks in retail channels.