If past is prologue, then GRH is definitely a great portent of what is possible.
The tech demo expands on the 2d side-scrolling nature of what was done in GRH to use more 3D assets to explore more interesting environments, but I hope it doesn't distract too much from story and character interactions, at least too much. I don't think the quick time events are as interesting as the choices they represent. If the Architect really leans into it, I suppose there can be more places of soft failure, say in a hamster ambush, that could lead to more natural branches for character development.
Mass Effect really lends itself to a wide cast of characters, so it's certainly ambitious, so I'm interested in how this will work. It looks like it'll start at least from the ME2 storyline, but could certainly be placed within the continuity of ME3. Everyone has a fan favorite.