The genre of tower defence games has been very popular for a few years now, especially in flash games on the Internet. Some developers and publishers, as we can see from Unstoppable Gorg, sometimes take the risk of making a pay-to-play version of the game. It's arguable if that is a good step, and everyone has their own opinion, but what I can tell you about this game in particular - Unstoppable Gorg is very innovative!
A different kind of video game requires a different approach to review, so this article might come out a bit different than always. I would like to start from a brief introduction into the story of the game. Everything starts on a peaceful day in the 1950s, when suddenly people notice an alien force approaching - called Gorg. Foolish people thought the aliens would come in peace, but instead they got war. You, as the player, are given the responsibility to hold off the attack and defeat the Gorg. To do so, you will have a chance to try your best strategies to mastermind a victory in over 40 challenges across the space - defending planets, space stations and other important objects.
Why is this game worth giving a try in my opinion? Well, the main reason is that it has brought a nice new innovation into the now rather old genre. The innovation is the orbit, to be exact. Unlike a typical flash-based tower defence game, where you just create your towers in suitable places and let the automated system do the rest of the work, in Unstoppable Gorg the player will have to constantly contribute to the battle through the orbital systems. Every level has more than one of those, and each orbit has a few spaces to build your spaceships in. What are the spaceships for, you might ask? They are the towers in this game, and you will have the chance to change their placement throughout the whole level, at least to some extent.
There are three types of spaceships: scientific, financial and defensive. The scientific ones are designed to constantly collect science points, which are used for upgrading towers in the next level. As a matter of fact, the upgrades do not stay for the rest of the game - in each level you will have the choice of choosing new ways of allocating the points. The second type, financial, is used to collect money. That is actually another difference from the typical tower defence game - your resources aren't generated automatically. You will have to build at least one of these in order to be able to build the other towers. Every spaceship costs money, and therefore you will often find yourself being frustrated due to the lack of funds when you really need them. The last type of spacecraft, the defensive one, is the main aspect of the tower defence games. These ships shoot the enemies down, kill the bosses and overall do the dirty job.
Now let's suppose the spaceships have been place into their right spots on the orbits and the enemy waves have started coming out. This is where the role of the innovations comes in - you have to manually rotate the orbits around the base, placing your towers at the right spots to shoot at the enemy. This might seem as a definite plus at first, but when you are attacked from more than one direction at once (and that happens quite often!), it might cause problems, because only the circle moves, while the towers are still attached to certain spots. This way a defensive spacecraft in a wrong spot will become ineffective while trying to defeat one wave of enemies - it will simply be isolated and unable to reach any alien. This is also the reason why the game requires more thinking than an average game of this type.
Leaving the innovations aside, I'd like to point out the good visuals of Unstoppable Gorg. Of course they cannot be compared to modern 2011/2012 games, but that wasn't the aim of the developers. It is just easy to look at, while being at least 10 times prettier than a flash-based version. I especially liked the 3D view of the game (a good addition to the genre). About the sounds - there wasn't any special atmosphere created by them, nor was the voice acting special. To put it into one word - average. On the other hand, there was plenty of humour in the black-and-white television cutscenes before and after the levels.
Finally I arrive to the main question - would I recommend Unstoppable Gorg to people? If you like tower defence games and don' mind paying a few dollars, give this game a try. It might be just what you were looking for. The innovative engine is one of the reasons to play it. If you don't enjoy games from that genre, this might not be a good game for you. The strategic thinking it requires is different from the RTS/TBS thinking, and the gameplay is in no way similar to shooters or RPGs. If I had to compare this kind of game to anything, I would choose Super Meat Boy. Both are good for killing some time, but lack the modern aspect of "gaming". As for the rating - I'd give it a 7.5, because it was fun and innovative, but lacked in some aspects.