Processor based Senior Design Project

I am an EE student interested mainly in computer hardware. I am trying to think of a senior project idea that involves CPU or GPU.

The project typically involves 2 or 3 students and can take a semester or a year at most. Othe student disciplines will be EE/CE or Computer Science.

I had an idea of perhaps implementing a processor instruction set on an FPGA using VHDL such that it emulates a processor itself. But I had a hard time thinking what else other group members could do at that point.

I'm not an expert by any means so any suggestions or ideas would be appreciated!