Congrats on the tunnel! Its a fine piece of work.
And better hurry and get yourself a porkchop.
Really? Flint isn't that tough. Just find a patch of gravel and bash away at it with a shovel.
What I was thinking of was just adding more rare types of blocks, or plants to the game that can only be found in widely scattered spots on the map (kinda like pumpkins). New types of stone, different color of flower, or if they want to get fancy, a new plant you can bring back and grow in your field. Or to get REALLY fancy, old stone ruins that have a spawner and treasure inside. Like an above ground dungeon.
Todays project - Gonna level the ground around my tower and build a fence, in hopes of keeping the hostile mobs away from my door. Then, I'm gonna grab my compass and bed, stock up on food, torches, and tools and go questing for cactus!