Getting past the menu only makes it worse

You're either new to Computing/Flash, or your source of education is lacking. The menu's options cannot be clicked (How to Play?, etc.) likely because you didn't link it properly to a related frame. There has to be a way to fix the bug. Try having a veteran in flash game development check it out. Forums are an option.

Gameplay: Interesting at first (intro), then a motivation landslide quickly occurred. (2)
Graphics: Lack of background. Bland art. (2)
Sounds: If there was any, I missed out. (0)
Controls: Entirely mouse-based for convenience but lacks hotkeys. (4)
Interface: Simple to understand but plenty of glitches/bugs. Lacks in-game menu. (1)
OVERALL: 1.5 stars

NOTES:
- Make a restart button. Or even better, a proper menu that allow pausing/speed control.
- Proper menu includes: Auto Pause?, Sound?, Music?, Quality: Low/High, Restart, Quit Level.
- What's the red bar for? What are points for?
- Wave start control.
- A "bestiary" for the enemies is suggested.

Once again a game that doesn't work, I'm clicking "Play Game" but nothing is happening.
You said to click it more than once, so I clicked it twice and still nothing, Let me know when you fix it so I can really share how shitty this game is going to be.

Obviously there are lots of improvements to make..

The one that sticks out to me is that you can stack guns on squares, i.e have four flamethrowers in one spot.

Evaluating

Nice TD game, but...
The game isn't made very well. I'll put together a little list:

1) None of the buttons, except the play button, work. When you mouseover them there's a pointer change only to the side of the text, which is a little diesturbing.

But I could start the game and it has a title screen and possible options - so here goes 1/5.

2) Intro. The frames don't fill the screen completely. there are ugly white borders.
2) Ingame. It says click on the screen to exit upgrade screen, but this never happens. It took me a while to find out what's clickable and what's not (like advancing to next wave).
3) When I finished the game, I didn't get any notifications on a win or lose. All my weapons suddenly disappeared. But STILL, I could upgrade the last weapon I had focused.

After that, I can push an upgrade button, which results in getting some hundred points added to the score each time I click.

You don't use any sounds, which isn't contributing to a better score.

So, this pretty much wraps up my review. You get another 1/5 for a working game and upgrade system.

Keep on practising! 2/5 3/10