Based on the answers provided, the following corrections need to be made to the 3D object:

1. Add a small circle centered at the bottom of the square. This circle is currently missing from the design.
2. Add four smaller circles positioned near each corner of the square. These circles are currently not present in the design.
3. Ensure that all the circles (the one at the bottom and the four near the corners) are slightly less extruded than the square.