Now, I'm not much of a Tower Defense fan. But I can begrudgingly admit that they're not terrible games, and that the strategies are rather nice. My problem usually rests in the slight random chances that lie into them, and the feeling that I get that there's sometimes no way to 100% of the time, finish a level perfectly. It always seems like there's that -one- wave towards the start where you're like "I NEED MORE TOWERS" but you just don't have the gold for it. And there's really no way you could -have- the gold unless you've found the magical layout that ensures efficiency.
Regardless, they're effective little time-wasters as games, and I would even call some of them fun, but most of them seem mostly there as a challenge than....well, something fun. Still, I have played a few that I would be able to recommend. Even if 'tower defense' is sort of a stretched term for one of them.
First up is Cursed Gems: Don't Touch My Stuff, which I just spent the last hour and a half playing when I became aware of the fact that playing some Kongregate games gets you points for your Powered Up Rewards, apparently. Get a badge, get GameStop points that will likely sit in your account forever because the rewards either suck or are presented at a radical price increase. But hey, you get Badges and Points! Win-Win, kind of!
Er, anyways, right the game. It's pretty much your standard fare, waves launch your towers kill, magic happens. Where it changes the 'formula' is that it gives you different terrain types on a map, and your three towers can only be built on specific ones, one each. Your grass lands are your Orc Huts which are basically arrow towers. Mountainous regions only support.....y'know, I forget. They fire a continuous stream laser. And your snowy regions are your Crypts, which fire magical bolts that I don't know what to liken them to. Homing missiles? Yeah, let's go with that.
That level of difference adds something to the gameplay, and they add another depth with Magic and, of all things, Trees. The trees fill up parts of the map that you have to use one of your spells to clear out, if you want to place a tower there. This is almost universally unnecessary, unless the trees are covering a mana font, which, placing a tower on it will increase your mana recovery. Or the entire map is covered with trees. But, as noted, there are some times when it's a necessity.
Of your other two spells, one increases the speed with which your towers fire for a couple volleys, and the other is a Meteor spell that deals big damage to an area. The former is almost never needed, as the only reason your towers aren't doing the job is because they're not properly condensed/upgraded, and is never something a Meteor can't take care of. The Meteor also being useful for Goddamn Ninjas and your large, boss characters helps speak for its value.
It quickly starts to feel like they're just throwing entirely too many waves of enemies at you, but proper upgrading and masterful use of both the "Skip to next wave" and "Double-Time" buttons make it go by at a much nicer speed for those who just want to finish the engagements. And it's practically for those reasons only that I can safely say it's a pretty alright game, since most TD games (at least ones I've played) don't have that and almost always get a little down-timey unless they just really destroy you with the amounts of enemies in waves.
The next game, Desktop TD Pro is actually pretty neat in its presentation and execution both. Now, I'm not quite sure how it was thought up, but if you start thinking about an ARI Glasses version of the game (considering the Desktop layout) it gets so much neater. Of course, this is still just played on a computer screen, but, still, it makes you think about these things and these things are pretty cool. There I go, talking about things that are -not the game-.
Anyways, what I like about the game, aside from the thoughts it gives me, is the fact that it gives you a flat board (Sometimes it puts towers in for you to start) and lets you set your own paths that the enemies have to survive through. So you always think of the best way to make this winding, painful conga line of death scenario, and the fact that you actually can do it is refreshing, as opposed to other games giving you the routes and you having to place within those confines.
Of course, eventually, they include enemies that completely ignore your confines and fly over the towers, but before then, oh boy, do you feel like you are some sort of tactical genius. And once again, there is the much appreciated "Next Wave" button. Maybe it's actually standard fare and I just completely miss it every time?
Now, this next one might be stretching the term a bit, but I still consider it to count: The Last Stand. Your towers, of course in this, being your fellow survivors that you recruit. But that might be getting ahead of myself in stating that. The Last Stand, unsurprisingly, is about the main character's last stand against waves and waves of Zombies. It plays out like a more hands-on Tower Defense game, you have your barricade line that you have to stop zombies from reaching and, upon failing that, stop them from wrecking it outright.
They come in waves through the night portion of the game, rationalizing the daytime section of the game is you dividing your remaining hours among yourself and any survivors you might have to repair the barricade, look for weapons, and look for other survivors. The latter two have a chance of losing someone along the way, which will often happen at the -worst possible moment-, but the rewards for searching for weapons are great, as the Pistol outgrows its usefulness....rather quickly.
Enemies upgrade just like any other Tower Defense game; they get faster, and they get hardier. Both running zombies and zombie dogs are added for the fast requirement, and Swat/Army zombies for the hardier; both require headshots, but the Army zombies also have helmets on, which means faceshots. And if you don't pick up any survivors to help you blast the undead, you'll likely get overrun. Even if you get the best weapons, if it's just you, it likely ain't enough.
So there are a few Tower Defense games that I've enjoyed, or at least can recommend to people who enjoy the genre. Certainly those of us reigned into it by PixelJunk Monsters need another outlet here and there, one that doesn't have the goddamn spiders of PJM, at least.