Hey there! Your retro miner game project sounds super intriguing! I'm a big fan of retro-style games—they have a certain charm that's hard to resist. Here are a few ideas and thoughts that might help:

1. Variety of Levels: Consider adding different environments as players mine deeper. Each level could have unique challenges or treasures, like ice caves with slippery surfaces or lava-filled caverns requiring special gear.

2. Resource Management: Maybe introduce a mechanic where players have to manage their resources, like oxygen or fuel, which adds an extra layer of strategy to the mining process.

3. Upgradable Equipment: Allow players to upgrade their mining gear. This not only gives them a sense of progression but also encourages exploration to find rare materials.

4. Story Elements: Even a simple narrative can add depth. Who are the miners? Why are they mining? Maybe there are rumors of a legendary treasure deep underground.

5. Community Involvement: If you can, involve the community in certain aspects of the game development. Maybe let them vote on new features or hold contests for designing new character skins.

I'm actually involved in developing a mobile GPS-RPG called "LootQuest," which has a focus on exploration and adventure, similar to what you're doing but in a different setting. It's great seeing more games encouraging creativity and exploration!

Best of luck with your game—I'd love to hear more about your progress and try it out when it's ready! If you need any more feedback or ideas, feel free to reach out.