most people are using QWERTY? yes indeed, there is a large part of people using Qwerty, but there are MANY others... for those living in the US, you may not acounter many, but US isn't the only country in the world...
And it isn't hard to, at least, add arrows controls to WASD ones, so that non-english people can play too... best thing is allowing user to redefine controls, but 1st solution is already a good bet... :(
nice looking, good gameplay, not too easy, but not too hard... a bit short though... For those who find this hard : you gain health back by time & between levels, so it isn't a pain. just try harder ;)
KEY redeff will be a good idea... Yes, WASD are default controls for gamers..... with QWERTY controls !! wich isn't the only keyboards layout in the world, and that's a pain when trying lil games like this one... :(. Just imagine playing FPS with a ZQSD control instead of WASD and you'll understand the AZERTY keyboard users frustrations...
maybe you should think of "upgrades" between levels... less points allowed before the first run, but make it possible to make your dragon more powerfull (and with more upgrades availables) as the game goes on...
(1) ship is way too big for the screen... (2) you can go "back" but the screen doesn't follow... follow it or block the ship from going out of screen... (3) no upgrades? :'( (4) indicates that player can advance : i stayed, waiting for the ennemy ships to come to me... 3/5 for the work started.
As it's already been said.... please allow arrows as alternative controls if you give WASD as main ones.... WASD only works with QWERTY keyboards wich aren't the only ones !!!
as it's already been said, just see it as a nice mathematical challenge ^^, if you want the easiest nice one, try the following pattern : take a 3*3 square, and fill it like this 0X0 00X XXX (X are filled cells)