I liked that the spikes appeared in already excavated areas, that was cool, unexpected and kept it more engaging. Although i wish the hit box on the spikes was smaller, there was times when I thought i hadn't gotten that close and died.
Also I think having either the controls on screen all the time or maybe hitting tab to toggle a controls info box would be helpful. I had to scroll down and reference it on the page.
In short... I dig it! (see what i did there? lol ok i'll see myself out)