Digfender, tower defense with a minor twist

Digfender
Grade: C+
Platform: Android
Genre: tower defense
Play Store: Free
Apple Store: Free
In App Purchases: Yes
Pay to Win: No
Released: 2016

I am a tower defense addict.  There's just something intensely satisfying about laying down defenses and watching hapless enemies wander through them until they die.  Or until they overwhelm you, though that's a bit less satisfying.

The game mostly plays like the average TD game but does so well, and has a few somewhat unusual aspects.

Generally speaking in tower defense games enemies either follow a fixed path that you must place defenses around, or you define the path for the enemies by placing your defenses.  In Digfender the twist is that the enemies are underground so you dig the path to them, then place your defenses on the sides of that path.  You don't have complete freedom in setting the path, not only are there some blocks you can't dig through, but you can't steer the path up once you've gone down, so you can't make it the longest possible path and due to the way they've set up enemies that might not be ideal anyway.

The towers themselves are fairly standard, there's freeze towers to slow enemies, and Tesla towers to zap them, cannon to hit them with area damage, and fire to surprisingly not do DOT until after an expensive upgrade. You get money for killing enemies which is spent on upgrades. Each tower can be upgraded three times normally, then branches to one of two specialties for the final three upgrades.

Where it differs from other TD games is in it's take on the standard tower types, and a few mostly cosmetic but enjoyable things.  For example, your freeze towers are also your sniping towers, which is not normally the way freeze towers work in TD games.

Digfender takes the not entirely uncommon approach of limiting upgrades until towers have gotten a certain number of hits on the enemy, which sometimes puts you in the awkward position of having plenty of cash to upgrade towers, but the towers being far from able to take the upgrade.  And since in late game spending the money on a new tower would be completely wasting it you have little choice but to sit on a cash reserve from time to time. But those sorts of limits are part of the challenge.

In the cosmetic but enjoyable category, Digfender leaves enemy corpses, but since they're climbing up the walls of the tunnel to reach the castle, when they die they go ragdoll and fall until they hit a horizontal surface, leaving a growing pile of cartoon orc and troll bodies as a tribute to the prowess of your defenses, and that's kind of fun.  It also lets you see where the majority of the killing is taking place and helps you plan your defenses accordingly.

IAP is limited to removing the surprisingly unobtrusive ads and buying diamonds.  The diamonds are used to buy super attacks to help you laze your way thorough a level, but are not necessary to win.

You can respec all your upgrades at will but it turns out you mostly don't have to.  Very occasionally you'll encounter enemies immune to one type of tower, otherwise you can win stacking any tower you happen to like.

There's nothing really groundbreaking here, but it scratches the TD itch well enough.  It's a good game for those new to the genre and has enough amusing little variations on the theme to be worth trying for longtime TD fans.