I found this by accident and just bought it. The best 15 Dollar I invested since Bastion. This game gets far less attention then it's deserve. For me this was much more fun then Dungeon Defenders. 24 levels, lots of traps, upgrades, spells and thousands of orcs keep the fun going for quite a while.
The first person perspective and "hack and slay" part unlike in other games do not hinder oversight or are in any other kind of way a hindrance. In fact for me it was a nice addition. Watching orcs being slaughtered, torn apart, burned, chopped to pieces, smashed or killed in many other gruesome fashions while I myself slice them apart with my blade stuff, snipe them with the crossbow or wreak havoc on them with one of the magic spells.
If you like tower defense and hack and slay you should check this out.