Here are a few things I like about those games:
Examples of games that qualify:
Examples that don’t qualify:
Games on the fence:
Basically, I want a game that forces me to learn and adapt using the limited tools the game provides. Here are things I absolutely want to avoid:
Basically, I shouldn’t have to think outside solving puzzles and fighting bosses.
Indie games are preferred.
Platforms:


A gaming community free from the hype and oversaturation of current releases, catering to gamers who wait at least 12 months after release to play a game. Whether it’s price, waiting for bugs/issues to be patched, DLC to be released, don’t meet the system requirements, or just haven’t had the time to keep up with the latest releases.
Keep playing TUNIC. It’s great.
Someone else mentioned Death’s Door which I see as TUNIC’s overlooked cousin.
Some others that are similar, have either played them or purchased and not played yet, due to similar taste to yours:
Alwa’s Awakening & Alwa’s Legacy
Anodyne
Blossom Tales series
Fountains
Lunacid
The Messenger
Moonlighter series
Unsouled