This book felt like historical fiction with complex themes inspired by The Island of Doctor Moreau, not leaning into the science fiction enough for me personally. P.S. I also love Mexican Gothic so much! Another slightly off-kilter retelling (as in not perfectly retold, but reimagined!) is Unwieldy Creatures by Addie Tsai.
Not a thriller reader but I do always feel a twist should not make or break and experience even if you guess it early or got spoiled for it. This one just felt so *fine* and underwhelming as a result imo