Tyrian 2000 is still one of the best PC shoot-em-ups and was released in 1999. The original game came with four episodes and the fifth was released later in the Tyrian 2000 version. It includes new weapons, ships and levels.
Tyrian 2000 is available for free from GOG.com and includes the whole five episodes with the Ship Editor to create your own ships.
Aim to buy the best ship you can afford. New ones will appear from time to time so make sure you check the shop after every level. Better ships give you increased armor. Check also for better shields and generators. If you run out of energy during a level your shields will stop recharging.
The weapon loadout is mostly for personal preference. For front guns the Zica Laser, Laser or Hyper Pulse are good options. Sonic Wave is great as a rear weapon. You can change the mode during a level to have the Sonic Wave shoot forwards as well. Other good rear weapon choices are the Heavy Missile Launcher or Guided Micro Bombs.
At least for the first and second episodes I like to use the Mega Missiles on the left and right. They only have 5 shots each but can be used to take down the end of level bosses in only a few seconds. This can be upgraded to the Flamethrowers when they become available. Other good options for the sidekicks are the Zica Supercharger, Dual Shot Cannon or Plasma Storm.
Main Menu Cheats
Enter these codes while in the main menu to unlock new ships. I couldn’t get these main menu cheats to work but maybe you’ll have better luck than me. Possibly I’m missing a command that needs to be entered before entering these codes or it depends on the game version.
enemy – Captured U-fighter
lizard – Dragon Ship
nortshipz – Nort-Ship Z
pretzel – Pretzel Pete Truck Ship
stealth – Ninja Star Ship
stormwind – Elemental Ship
techno – Experimental PQZ Ship
unknown – TX Silvercloud Ship
weird – Foodship Nine Ship
Enter these cheats while playing through a level. You’ll know it’s worked if you see the message “Cheaters always prosper”.
[F2]+[F6]+[F7] – End level
[Backspace]+[Number Lock] – Full pause screen
[Backspace]+[Scroll Lock] – Random Background Music
[Backspace]+[Minus] – Random Colors
[F2]+[F3]+[F6] – Toggle Invincibility