Also, I just wanted to say that while most of the comments have been about problems in the game, I think it's safe to say that we all like the basic idea, and look forward to seeing the developers expand upon it.
While this is no Bloons TD, Gemcraft, or Cursed Treasure, it definitely shows some innovation in game mechanics, and it could either grow into something great or serve as the precursor to another project. So get back to working on balance and clarifying the mechanics (and if you get a chance, teach the guys at IriySoft how to make hotkeys).
Enjoying the game, but a minor nitpick: When I'm upgrading towers, I see "Build Speed," but I don't know what that means (and it isn't explained). Unless I'm mistaken, towers appear instantly -- does this relate to the mana regen rate, or is there something I'm missing, or what?
I'm giving it a 5/5, both despite the length and because of it. It's an excellent game, and I want lots of people to play and enjoy it, so that the creators can see that there is a great demand for more.
More, I say!
ArcanisX: The game itself gives you a pretty big hint at the start of the level. Use the new lightning upgrade in combination with some cannon towers to hits lots of them at once for lots of damage. Also, make a cannon tower or two at the start with ice upgrades, so that the creeps will all be grouped tightly together by the time they reach the lightning cannons.
I have an odd problem. I cannot play the game, because most of the time the game is "zoomed in" when I select "play" -- putting most of the Custom Cell option off-screen, as well as the option to proceed. On the few occasions that this does not occur, the problem resurfaces when I attempt to level in-game. For the record, my flash player is not zoomed in, and this problem occurs the exact same way in Firefox, Internet Explorer, and Opera. It looks fun; I hope you figure out what is causing this.
Brilliant. Simplicity of gameplay but depth of action. It is exactly what it intends to be, and that is epic. Nothing more, nothing less.
Don't be distracted by the hold-button-and-move mechanics. This game is basically all those bullet hell final bosses condensed into a package of awesome. Don't forget that games are art.