With so many options at your command, Defenders of Ardania tries to overcome some shortcomings by incorporating some new innovations, and while this works somewhat, the fact that these shortcomings exist does hinder the overall enjoyment of this game.
Every important piece of Defenders of Ardania is individually well done. The factions are similar enough to feel balanced, while different enough to maintain distinct identities. The models are attractive; their designs innovative enough to avoid an entirely generic feel, and even the levels in which they appear are interesting.
It could be a very good game and although it's not specifically been done before it just seems to defeat itself. It's neither a RTS nor a Tower defense game. Defenders of Arcania doesn't do either really well and it doesn't know what it wants to be which is a shame really.
In conclusion, Defenders had the basis for a good game. The developers have tried something different, but it hasn't worked this time. The gameplay just comes across as uneven. Certain units should be strong against some towers and weak against others and vice versa, instead of every unit bar one being weak against everything. Unfortunately, this game simply comes across as a chore to play, rather than a joy.
Defenders of Ardania is so bad, it's bad - and I don't make that statement lightly. It's filled with idiotic design decisions and gameplay imbalance. I had an utterly miserable time with it, and I never, ever want to touch it again.