In my review of Incursion, I noted that Incursion showed a clear line of descent from Monsters TD and Keeper of the Grove, previous games created by the same individual. Incursion 2 is a further evolution.
Most aspects of gameplay are identical (and this is a good thing), but the biggest change to gameplay is one that I'm ambiguous on: The spellcasting style that carried over from Keeper of the Grove has been replaced by heroes.* (Note: These pictures are durned tiny, so you'll probably want to open them in new tabs/windows to view them if you want detail.)
Now, I'm not against heroes in principle, and there are clear advantages to them. The main problem is that their interface is a bit clunky compared to the old spells, and it might be just me/my computer, but particularly on certain missions I'm prone to not having my clicks go through and getting stupid results out of the guys (I can't tell you how many times I tried to select a hero's ability and it just didn't take, resulting in me trying to give a hero an order to use said ability and instead having him march off somewhere stupid). There's also the fact that your heroes can die, and while they come back to life free of charge, if one is trying to rely on their abilities this is a problem-there's no way for an enemy to prevent you from using your spells in the previous game, even if you aren't guaranteed to have any at all. They're also prone to running out of mana if one is like me and doesn't bother buying them potions.
That aside, I mostly like them. Each hero has some spells that he can cast; the main hero has a wide variety depending on which of four schools of magic you choose, while there are two other heroes that help out on specific missions. The first one of the "allied" heroes has some pretty sweet archery-inspired abilities, while the second, a member of the "Strygweers" (see below), is... kinda subpar, and tricky to use to boot.
Thus far, I'm quite partial to the Mors (death) school of magic the main hero can use, which grants abilities built around summoning undead minions. These abilities are super-useful because you can summon meat shields wherever you need them; while all the guys summoned this way have timers that make them evaporate after a while, it's often not relevant. I'm kind of curious about how the Vita (life) school plays, because it's got a couple of pretty nifty abilities too.
I don't think these particular guys are my favorite Mors summons in terms of gameplay, but they're definitely the cutest little chestbursters.
Most of the rest of the game is additive, such as its addition of a whole new category of defenders, the Strygweers, who are some sort of blue catfish/salamander people with potentially unfortunate accents. The Strygweers don't add a huge amount to the game, being used for, like, one stage, but they are at least different, and I do appreciate that, anyway.
I think their main problem gameplay-wise is their uniformity; it's hard to tell which Strygweer units are supposed to do what, and they ultimately all cost the same. Using them for more than one mission would be awkward, as well, because they don't interact with the game's upgrade system, and that combined with the fact that the basic Strygweers are very noticeably more expensive than the upgraded mages (who are the most expensive normal units-note that when I say this, I'm referring to the out-of-battle upgrade system, which involves reducing said infantry's cost, and I'm not counting the in-battle individual unit upgrades-admittedly, the Strygweer only upgrade twice per unit, while normal units upgrade up to five times per unit, with branching paths after the second upgrade), and a fully upgraded mage-family unit is still the strongest thing in the game by far.
In fact, while the Archmage has been toned down a touch with the addition of a timer on his summon so that they don't just act as indefinite meatshield puppets the way they did in the first game, he and the (one step down the upgrade path) Lightning Master are still the strongest things in the game, as chain lightning is just so good; arguably, the game could use a little shaking up to keep it from being all about amping up to Archmages (which, if one looks at a later screenshot, one will notice that I am very prone to, having filled five garrisons with three Archmages apiece).
Archmage spam doesn't keep the game from being fun, though. The game retains nearly every enemy from the first (lacking only a boss), and then adds over twenty new ones, resulting in more than fifty different enemies. Some of them are stage-specific, and a few of them are bosses.
I should note that there are unit names here and there that are pretty odd; the first game had "Shaman the Patron," who obviously makes a comeback here, and this game also has "Queen of the Spotless Mind," which somebody thought was an appropriate name for a mind-controlling alien lady.
Anyway, while a few of the new enemy types are just additional vanilla variety enemies, a high proportion of them are unique in one way or another, and they add a lot. The aforementioned mind-controlling enemy varies between being hilariously harmless (oddly enough, in her introductory stage, where a feature of the area makes her a lot less likely to do much damage) to really darned annoying, which is what generally happens when she manages to hit the hero. (Although the hero's special abilities are still under your control regardless of the mind control.)
The game also has an honestly hilarious unique scenario where the enemies are actually derivations of the units the player controls.
It's actually kinda painful because the game's creator seems to be assuming that a lack of the annoying abilities the enemies have would make the level too easy, and so they just come in ridiculous droves instead... and whenever enemy Lightning Masters/Archmages/honestly any ranged units (though the chain lightning boys are the worst) show up you're generally in for a hurting.
Anyway, as noted when I talked about the first game, another thing that keeps the game addictive is that it not only has solid gameplay otherwise, but it also has varying scenarios wherein there are different special hazards, allies, or support powers to spice things up. Such as this hilarious machine gun that you get when you successfully reach the end of one mission, which you can "rent" the use of in the item shop afterwards.
There's also some story in there somewhere, with an actual narrative of sorts, but it's pretty basic.
The final verdict, predictably, is that Incursion 2 is a game that you'll enjoy if you enjoyed Incursion. I don't think I'd ever say this is a better game than Incursion, but I can't say it's actually a worse one either.
*In the interest of full disclosure, I should mention that, with the heroes particularly, this game