I think this game has potential, but it's also got some large flaws.
In my opinion, implementing an upgrade system could make the game more interesting. You could have three different types of upgrades: strength, anvil, and thirst. Each upgrade can be bought with skill points.
Strength upgrades could allow you to click more per second, since it seems you've put a cap on the cps possible. This could go up in increments of 10 cps, or 5 cps, it depends on the type of gameplay you're going for.
Anvil upgrades could produce more skill points per click. This would probably double over each upgrade, ex: 1x, 2x, 4x, 8x, 16x, etc....
Thirst upgrades could allow you to drink your coffee quicker. I like the coffee mechanic, it makes your game unique, but at it's current state, it's more of an annoyance than anything. If you added upgrades that reduced the time needed to drink coffee, this could make the game much faster paced.
I think this game has potential, but it definitely needs work in its current state. It's fun for the little gameplay we have, though.