You are changing the 'Board' to be the 85, right? You cannot just load Uno or other code into the 85 without selecting the right libraries.
In principle there is nothing in the code that assumes a specific processor and no direct to hardware code or oher tricks are used. What can change is the speed of the processor (MHz) and how the libraries are constructed for the new device.
When I compile my version for the Uno I get
Binary sketch size: 1,436 bytes (of a 32,256 byte maximum)
If I select the 85 my IDE will not even comple the code, and I see from the datasheet that it only has 512bytes of SRAM, so the code may not even fit if it could get it to compile.