If it makes you feel better, I had that same feeling with Breath of the Wild, Metroid Prime, and Resident Evil 4. My top 3 favourite games ever, from announcement to hype cycle to release.
Astral Chain is not the case like The Wonderful 101 or Kid Icarus Uprising or Starfox Zero where the writing was on the wall. Astral Chain, so far, doesn't seem to have any major control/gameplay issues. It's all been pretty positive.
I think the worst case scenario, review wise, is it lands around the 80MC mark, being just a good romp and nothing more. I sort of don't get the impression it's going to be a 95MC or anything, people say the game is good fun, but I havn't heard too many impressions saying the game is incredible, amazing, or breathtaking.
I would predict an 85 on MC. I know discussing/guessing MC scores is lame, but I find it fun.