Looking for a robot anime from ten years ago

Help! I watched a robot anime on TV when I was a kid, but I don't remember many details:<br><br>- The main mecha is red<br>- It uses a drill as a weapon<br>- It seems to be about underground dwellers attacking the surface<br>- It should be a work from before the 2010s<br><br>Does anyone know what this is? It's been bothering me for a long time, and I haven't been able to find it...