I know plenty about platformers and each game has a different focus. The moveset of AstroBot is limited, but that doesn't mean it's not a good platformer. They explicitly use all of the little moves you can do (and powerups) to create an experience that is challenging for those specific levels.
A platformer doesn't need to be difficult to be great. I didn't find the galaxy series to be anything too insane, but it's one of my favorites.
What sets AstroBot apart is the attention to detail in its moment to moment gameplay, where everything feels fresh and paced to perfection. In terms of production values and pacing, it's basically near perfect, and the boss battles are far more interesting than the recent mario games.