Thexder is a transformer space shooter with some variation possible in paths. The action is solid and the graphics look nice. The firing leverages an auto-targeting rapid fire mechanism, so you don't really have to worry about enemies coming from different angles, but you do need to be facing them. From that perspective, it's quite satisfying.

The tough part about this game is transforming from your robot state to your spacecraft state. Transforming itself is easy, but takes a lot of getting used to navigating narrow passages. If you are in your spacecraft form and try to take a turn a bit too early, you hit the wall and are automatically turned back to robot form again, having to re-transform and retry your approach.

This is the FM-77 version, so comes on 3.5" disks and is compatible with the FM77AV, despite what the box says, but it doesn't support FM sound. The box and floppy itself were really dirty when I got them, but the box cleaned up nicely, and I managed to clean up the floppy media well enough to check that it works.