Yes, Nokia 3.1 Plus is made of aluminum. It is one of the most strong built mobile phone from Nokia.
Nokia 3.1 has 18:9 aspect ratio with 6-inch display.
Nokia 3.1 Plus has a gyroscope, compass, proximity sensor, ambient light sensor, accelerometer and fingerprint sensor.
Yes, Nokia 3.1 Plus does have the fingerprint scanner, which is located at the back side of the phone.
The Nokia 3.1 Plus is not the most competitive phone at its price level; not by a long shot. No matter how good it looks on the outside, it's hard to ignore just how much smoother the usage experience is with other models.
Overall, the Nokia 3.1 Plus has a vibrant display despite being of HD+ resolution, and the phone offers good battery life too. I even like the design, especially the aluminum back and soft rubberized finish.