I built a gamified walking tracker for myself, and I'd love ideas for its rewards, dares and secret

I've been building a gamified walking experience to help me move around. Each day it offers walks at different difficulty levels (with real walking-route distances, heat and daylight checks), and walking earns coins, trophies, pixel-art gear and creatures that evolve as your total distance grows. It also hands out random rewards, dares and secret quests and locations. It's a hobby project: Node + SQLite, vanilla JS with no build step, self-hosted in a container behind a Cloudflare Tunnel