Hooookay. Been done before.
This kind of thing has been done before, the only real change is that you have skulls on the shapes and you took out a lot of the upgrades that are normally in the game.
The art is alright, the blood effects are basic and copy/pasted and turned. There aren't that many of them. I'd put more kinds in or an automated random blood generator... or something to that effect. The enemies are shapes (duh), and the cannon is a circle with a rectangle on it (basically). I'd improve these, as really, "shape defense" is kind of overdone, over made, and not very original.
Upgrades are really self-explanatory. You have healing. You have increasing of health. You have the common cannon that shoots alright, and does decent damage. You have the slow-shooting, accurate, and burst-damage sniper. You have the common machine gun, and basically a mini gun, thought you're calling it a "cluster". I'd upgrade to have some seeking rocket-type attacks, a close range laser that hits one-two enemies at a time, mines that you can place, blocking walls that eventually are destroyed after blocking too many enemies... stuff like that.
Music is alright. It fits well. There's muting of sound. Don't have much to say on this.
The controls are ok. Simple, just point where you want and click to fire. Can't move your turret... Wish you could do that.
Overall, it's a basic stationary shooter game. Not much to make it special, and it's not overly original, so it's kind of just... boring. If you had a bit more to make it original and special, that would be a good thing and make it much more enjoyable.
-Review Request Club-
Far too simple
Sure enough, it is an entertaining game, but it's just far too basic.
I didn't feel there was much of a learning curve to it, and the game mechanics were very simple, just never gave me a challenge. Simple point and click, or hold down the mouse. Upgrade now and then, when you've got the money. I only got to the sniper rifle, because I simply grew bored of the game.
The graphics are really simple, and I feel "Shape Defence" is a far too simple idea. Shoot shapes with skulls on them doesn't really get new. The menu looks pretty neat, however, and I like that the options menu is quite simply right there. The general graphics are simple and could do with some work. A health bar, some graphics for the coins, more original enemies. Right now you just get all the different types thrown at you at once. I'd rather see just one enemy the first two or so levels, and then more and more as you go.
As for upgrades, they're very simple. Defense games often have some sort of perimeter defence upgrades of sorts, if you know what I mean. Sandbags, spikes, traps. Simple upgrades that add a lot of variety to the game and change it a lot.
Music is good, but I'm glad you have a mute button. It is fast-paced and action-packed, which is why it suits a game like this very well. Add some sort of achievements to this and I would probably play it just for the achievements. Just add a goal, or something like that, something to work towards.
Review Request Club
A bit too simple for my liking.
It's a great game, don't get me wrong, but I think it's a bit too general. There are a lot of defense games out there, and for a good defense game, you need to stick out.
Everything works fine, and it's not way too easy (at least not for me), but the game doesn't change enough from the beginning. The only thing that changed is that the enemies had more HP, and that there were more enemies in general.
Maybe you could make an useful weapon that's not too expensive, or make the money you earn could be a bit more. Or at least make something else upgradable about the weapons, like fire rate +10%. It would be funny to have a bouncy weapon, or an strong, cheap, but unreliable weapon. Something you can think about whether or not it's worth of equipping. Because now, you just have to equip the strongest weapon you can afford, and upgrade it.
Maybe you can even make it so you can change the appearance of the cannon? As in different colours, or a polka dotted cannon.