I played Motherload, the flash game on XGen's website years ago. What kept me playing was the fact that I was making progress despite starting from the top again at times. Digging into the earth, harvesting minerals, returning to the surface to sell, repair, refuel, and upgrade is the norm for the game. For others it's tedious and mindless because it is just lather, rinse, and repeat. For me, it kept me entertained when I had nothing to do.
Super Motherload brought that formula and gave it an overhaul. Everything was updated and upgraded. There are even outposts to reduce many needs for a teleporter, which is commonplace for Motherload. The basic mechanics were still there but there are no longer those pockets of gas that instantly destroy your pod. Replacing it is magma and metal blocks which require certain explosives to do so.
To be honest, this game felt a little shorter than Motherload. However, the reason Motherload was longer is likely the lack of those outposts and the gas pockets.
tl:dr This game isn't for people who like tedium, like Minecraft and Terraria. For the others, I'd recommend checking it out.