Unlike everyone here, im afraid i just dont have anything bad to say, even less regarding the graphics; i think they are superb, and the detail that Pkmays mentioned above, striked me on the first run.
I love the feel, and look of the game to the very bone, and dont find it boring at all, like Helm, and, yes it brings all sort of sweet game memories to me.
All i could offer are some gameplay features,
Like making the chain system more noticeable, in fact, that was something i didnt noticed until the second run, and even then it distracts me to look to the bottom left of the screen, to check the screen status; it should be above, next to the power up energy, or shown on screen when a ship is destroyed (despite it may look a bit more crowded).
The slower speed of the ship when the gun is jammed should be even more noticeable than right now, theres not enough difference right now.
Add a laser beam (blue for nostalgia sakes) and a homing missile as a sidearm, and i will be in heaven.
Im eagerly awaiting for a full release, and really you should be proud of what you have in your hands.
Cheers, and kudos to ya!
EDIT: 484.085 and lost only one life against the boss right before the end!, wich reminds me, when you start gaining up lives (wich i think are a bit too much) they become unvisible because of the power up bar.