Yes, dead on .. its an arcade game.

I would whole heartedly agree with Korrin below, this game play tends to lose out quiet fast. But here are my thoughts. Since this game does not have any power-downs if you shoot the wrong think, might as well eliminate the fact that one has to press the LMB to shoot, have it shoot continuously. Space out the powerups and shields a bit more so it forces the player to be more careful, currently one can be very casual and just break though the enemies since there is always a shield around. I do like the designs on the players ship and the evolution of the enemy ships. The astroids look cool too.
Like mentioned earlier the game play gets repatitive too soon, if there was even a small mission like stay alive for x seconds or cover this distance which is shown though a progress meter, this may compel users to play the game more strategically. (Though I get the fact that this is meant to be an arcade style game).
Overall I must say, this is a good first game submission and looking forward to a next build

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Cheers!

Repetitive

The game has decent basic controls and even some upgrades, but it gets very repetitive very fast. There aren't many enemy types and there seem to be no levels or waves or any other progress indicator (I got score "a", so no point even in a high score). It seems that there are so many shield and repair power-ups that it barely matters what you do, you just can't die as long as you keep shooting. As the result of all this it gets boring pretty fast. So far it's just little more than a decent shooter game engine really.

What can be improved? Well, if the power-ups are more balanced and boredom stops being the primary reason for finally dying, then at least playing to see how long can you last could be fun (more enemy types and working scoreboard is a MUST for that, too). On the other hand, if you make some levels, interesting wave patterns and a story, the game could be fun (don't forget bosses, they are a MUST in this scenario... also more upgrades will be needed). Or do both: make a game with a story and an endurance mode.