Simple, fun but...

Would it hurt to use a little colour? Sorry but the visual wasn't interesting at all, however the gameplay was.
I liked how every round you were given a new turret. The upgrades were pretty cool to. They did make it a bit easy though but it was a good fun 2 minutes.

I know graphics aren't everything but it is recommended that you add some colours.

Nice graphics but...

The tutorial has too much control, I was too impatient and started clicking, figured things out and now I can't progress any further because the game is asking me to purchase an upgrade which I have made already!
Please fix this small issue :(
Graphics: 9
Very nice, the buildings look very well done. The scenary looks cool, however the units could have used a bit more attention in my opinion. However if this was done for optimizing, ignore that last part!
Sound: 7
The enemy deaths sound all the same, could do with different noises for different classes. Nice little battle track at the start of every wave though. Ambient sounds is a nice touch whilst in Idle mode.
Gameplay: 9
Plays like any other defense game with a fixed income economy, making you really think about the purchases you make. Instead of having to sell units at half price you can remove them into your sortie which is a nice touch. Game has hours of amusement for defense fans.

So frustrating!

Thats what makes it fun and addictive. I can easily spend a few hours playing this game. I have wanted to punch myself in the face for getting greedy trying to get the powerups only to end up dieing. Sometimes I would scream when I was near the top on a part where two bouncing enemies usually show up and knock me down into death. Others times if I stayed too low the blue dispearing blocks would be the end of me. The game forced constant decisions which is nice to see.
I like how every replay is different and well it seems the enemies spawn points are also moved around.
Good use with coloured instructions too, made it clear and simple to remember.
I did however find some difficulty getting up the ladders now and then, which maybe you could implement some frame lock or something so when your near the ladder you can latch on. It might make it too easy though.
Overall the game is what all games should focus on which is fun, simple and yet insanely addictive.

Good but...

Needs more whitenoise to help visualize the ocean. Still good job though :)

Nice and light

I can see this being used as a track best suited with a puzzler game or maybe a menu loop.

Very nice

I like the twinkle, however I think you should have tried different percussion or maybe stripped it out. This song could sound like alot of things.