Thunder Cross is a mid-school (not old or new) horz shooter with some unusual weaponry. It has a nice graphical presence and some good variety in what you wind up battling.
You play the game with a joystick and two buttons. On the original control panel the buttons were called "shoot" and "super weapon". But that's somewhat misleading. The 2nd button does nothing until you get a satellite/pod to join you. You do this by grabbing the "O" (for "option") floating power-up. You can actually gain up to 4 satellites that all fire simultaneously and make you pretty studly. So, now that you have a satellite, you use the 2nd (super weapon) button to move the satellite further away or closer to you. It simply vacillates nearer or father as you hold down the button but always stays parallel to you. So you can pull it close (like a double shot) or push it far away and have it fire at stuff while you are not in harm's way.
In fact, you don't have to worry about your satellites getting blasted or running into things. The only way you die is if your main ship gets hit or smashed. Until then, you keep all your satellites. If you do die, you lose them all. So in some cases, you can shoot at stuff that is hiding behind rocks and things with your satellites that you couldn't aim at with your ship (you'd smash into those things).
So where's the "super weapon". Well, once you have satellite pods, you can possibly get other power-ups that give you lasers, napalm and other stuff. When you get these power-ups, your satellites no longer shoot when you do normally. Instead, the 2nd button becomes the fire button for the super weapon that is fired from the satellites only (not your main ship). Keep in mind that all the Super Weapon power-ups have limited use. A gauge pops up when you are armed to show you how much you have left.
The graphics are nice. While the backgrounds aren't great, the enemy ships are sharp and colorful. Also, there is a nice variety in what you see. On the third wave/level, there are indestructible obstacles like ships and space garbage that you have to avoid smashing into while you fight the enemy.
All in all it's a fun game that'll keep you playing for a while with nice a weapons system, good controls and solid graphics.