Mixed bag

Grapihcs - Player looks like a ps1 gamepad which is bizzare, but not necessarily bad!? Other than that I can see a fair bit of work has gone into the enemy sprites and they all explode in a satisfying manner. On the flip side the backgrounds are painfull to watch!

Sound - neither adds to or detracts from the gameplay. (ripped) music seems to go ok with the game

Gameplay - Well this is your basic space invaders style move left and right and shoot at the enemies at the top of the screen. Nothing wrong with that. Other than that some interesting ideas have been put in which sadly don't deliver as well as they could have...
Firstly you have an energy reserve of sorts which gets depleted when you fire. Top it up by scoring kills and collecting pickups. Unfortunately this feature is largely redundant as you can hold down the fire button throughout the game and rarely will you be at risk of losing energy, which is a shame as this could have resulted in some tense and tactical shoot outs!
There are also various collectibles you can get which help you on your way (increased power, energy and health top ups extra lives etc. Would have been nice to see some more exciting power ups however.

Enemies mostly act in a very similar way and move a little too fast for my tastes (that or your bullets move to slow!). Though variety is added towards the end of the game.
Bosses are a different matter altogether, a lot more thought and imagination has gone into their design (even allowing the player to move up and down for one of them to avoid fire from all directions) and these sections were a lot more fun to play.

Story - Story is told through textbox, however, space invader style games are usually completely devoid of story other than 'they're from space and they're invading - shoot them!!' so the inclusion of a more developed story is welcome. While it is by no means a great story it does come to a surprising and borderline poignant ending!

Interface - Everything works and controls as it should, there is not a great deal to say here.

Overall - there are a lot of better games on the site to while away your time but then there are far worse out there too. It's certainly no bad way to pass the time if only for the boss encounters! Other than that i can say that some of the gameplay ideas are great (even if the implementation is far from perfect) and hint at good things to come from the creator.

Keep it up!