We present a semantic feedback framework for guiding the evolution of artificial life systems using natural language. By integrating a prompt-parameter encoder, a CMA-ES optimizer, and a CLIP-based evaluation, we allow user intent to drive both visual outcomes and underlying behavioral rules. Implemented in an interactive ecosystem simulation, the framework supports prompt refinement, multi-agent interaction, and emergence rule synthesis. User studies demonstrate improved semantic alignment over manual tuning, demonstrating the system's potential as a platform for participatory generative design and open evolution.