Mytheria is, sigh, another card game.
This is going to sound like I'm picking on Mytheria, and I don't mean to, because at least in some ways it's a good game, but I can't help but feel a little frustrated at the current state of Flash gaming. The advantage of Flash gaming is that it's supposed to be this open playing field where all sorts of independent, crazy ideas can flourish. However, it seems like the lion's share of the most popular games on Kongregate currently are either sequels or one of the most popular categories: tower defense, card games, survival shooters, or dodgers. (To be fair, looking at the most recent challenges, this seems somewhat less true than I make it out to be. I think it's just the current profusion of sequels which is dragging me down a bit.)
OK, so Mytheria is a card game. The natural temptation with any card game is to compare it to Magic, and indeed, Mytheria is very much like a stripped-down version of Magic. There's no lands, but otherwise the procedure is very much the same: you use mana (which comes in five different colors) to play creatures, spells which have an instant effect, spells which enchant a creature, or spells which have an effect on the whole battlefield. Those creatures then attack; attacking creatures can be blocked by other creatures, in which case usually one or the other is killed, while unblocked creatures do damage directly to the player, and the objective is to reduce your enemy to 0 life. Some creatures have various special abilities -- some can assist others in blocking, some are unblockable, some can only be used to block, not attack, and so forth. These will probably sound vaguely familiar. There's even a Tim! And your cards have flavor text which often hints at some bigger plotline which is never really revealed.
Anyhow, what makes Mytheria different from Magic? Well, a few things. Perhaps the most obvious and important difference is that Mytheria has far, far fewer cards (83, if my count is correct), and those cards are pretty straightforward -- there aren't any Chaos Orbs lurking, for instance. This makes the game much more streamlined. Also, as mentioned earlier, there's no lands; rather, at the beginning of the turn, you have the choice of increasing your power (which effectively means playing a land) or drawing a card. This removes some of the frustration of never being able to get the land that you want (or, conversely, too many lands), while adding the tactical decision of whether to draw or increase your pool of mana. This sounds like a pretty clever design. However, in practice, it means that all you do is increase your power until you have enough mana to play everything you have lying around, and after that you draw cards, so it ends up being not quite as tactically complex as it first appears. The next difference, which is quite significant, is that you can only play cards at one specific point: during your turn, before attacking. This eliminates huge swaths of the Magic strategy space: no interrupting your opponent with Counterspells or the like, no strategically-timed Giant Growths or Lightning Bolts during the attack phase ... you get the picture. This makes the game vastly simpler (and, undoubtedly, much easier to program). Finally, instead of creatures having a different attack and defense/HP, all of those numbers are rolled into one "Strength" number, which is both a creature's attack power and its HP. When a creature takes damage, it does not immediately recover like in Magic; rather, its Strength recovers 1 point per turn until it reaches its maximum. The observant Magic player will note that this makes wall-type creatures incredibly powerful: not only can they cheaply absorb a lot of damage, but since they do an equal amount of damage in return, they can destroy even the most powerful attackers.
The basic framework of the game is pretty simple -- you have 12 missions, which you play with a fixed deck against various opponents. After completing the sixth mission, you unlock the challenges. In the challenges, you have to build your own deck to defeat a variety of different tasks (you start out with very little health, the enemy starts out with a lot of health, etc.). The main problem is simply that the game is too easy -- the AI is really not very good, and the missions are pretty fair, so you should have no problem rolling through them (I didn't die once my first time through, although I did manage to get killed a couple of times replaying them). Deck design for the challenges is also not hard -- you just need to pick one of the colors and build a good deck. (You might think that the fact that you can freely pick which color to add when you increase your power would encourage multicolor decks. However, the vast majority of the cards require all colored mana to play; not many call for any colorless mana, and only a few call for more than 1, so in practice, single-color decks tend to be the most effective. This is kind of unfortunate design.) Because of the small number of cards (and the fact that the card balance is not so great), building a powerful deck is not a difficult task, so you also shouldn't find the challenges too difficult.
To give credit where it's due, Mytheria is a lovely game. The art is very nice and the backgrounds are beautiful. The music is minimal but a nice touch, and the sound effects are varied enough that they don't become completely boring instantly. The interface is also very nice-looking, but it's awfully slow; I had to turn the message speed up to maximum to make it tolerable, and while creature combat is still annoyingly slow that way, instants often flash by too quickly to notice, which is kind of aggravating. (Another poor interface feature is that when you play a card requiring colorless mana, a dialog box requiring you to pick the color you want to use pops up, even if you only have one color available. Annoying!)
Anyway, if you play Mytheria, you can enjoy the pretty pictures, and it won't take you very long to finish. So if you're just in it for the badge, it's not too bad. Still, it's kind of a disappointment, simply because with more cards, better card design and balance, and more challenges, this could easily be a really good game, but as it is, it's just kind of blah.