Damn. And the one on Epic's site is long gone. (They're making a version for the gba that they want to sell). Um, [Try this one] non english, but zipfile seems to exist.
Full of secrets, upgrady stuff and things that go boom - in a lot of ways the shareware verison is more satisfying than the full game - because the full game gets HARD.
I'll edit that slightly. The first episode is not quite long enough for you to afford the very best guns. But after you do get to the point where you're using the best guns, you find there's still four episodes to go, and the enemies keep getting stronger. It's still pretty easy to finish though. --Vitenka
Oh, additionally - you can play it two player. Both on screen at once, with an added 'docking' mode, where one gets to control the turret and the combined ship pours many many bullets onto the screen.
Sample secrets include many many bonus levels, ranging from normal added levels, through to time limited levels and quick mockeries of space invaders. Also additional new weapons (some effective, some silly) power ups (soul of zinglon is my favorite, others prefer the attractor or inferno) and ships (carrot ship!)
Oh - there's also a set of 'combo moves' much like a BeatEmUp? (or, more recently, UnrealTournament?) where jiggling the joystick a particular way gives a temporary power tradeoff (most of them cost something as well as doing something) and all of those are secrets (of the 'we reveal some in the end of episode hints' way) as well. Argh! --Vitenka (Luckily you don't need them.)