It’s actually very addicting once you play a couple of sessions. The scoreboard is crazy. Still don’t know how anyone makes it past wave (layer) 35-37.

It basically has the same gameplay as ProgressQuest, an adventure game that was famously created to minimize user involvement.

https://progressquest.com/play/newguy.html

It's like cookie clicker, with less clicking and more blood!

Once you get high enough you can switch commanders which gives additional upgrades and active powers.