I really liked this game. I played it twice through and I'd have to say that I really enjoyed each time I played.
Above all, the graphics are simply amazing for a BASIC game. I love his tile designs - most of them really help you set different parts of the spaceship apart, and the ones that actually have other functions (such as the save platforms) do a great job of showing what they are. Not to mention the bosses - those were great!
I also like the storyline - while the idea of being kidnapped aboard a ship is not new, and the dialogue is a little weak, it's still riveting in that you really want to see what happens next. And it's not just the cutscenes (which were quite well done) but also the gameplay elements themselves. This is really rare among calculator games, especially BASIC ones.
The gameplay itself was quite nice, quick to pick up and run with. I really like how vast the ship is, and how, as you play through the game, discover all of its rooms and locales along with how to navigate through them efficiently - it really is an elaborate maze! There were some gameplay elements that did irk me a bit, such as there being only one bed and the tendency for bullets to skip past enemies, but as I continued playing, I realized that they were strategic elements, quirks that you must master in order to master the game.
And then there is the replay value. I think that his Cargo Capsules idea is pretty dang marvelous, since it forces you to look through every nook and cranny of the maze. However, since it is impossible to permanently miss any Capsules and there are no other measurements of replay value, such as a death count or time lapse, the game can really be replayed only once.
Overall, I think that this game deserves an 8/10, because while it does have some gameplay quirks, it makes up for them with its great graphics and storyline.