How to play Thunderground online
- Dig and drive: arrow keys (up, down, left, right)
- Fire the laser cannon: Space bar (it shoots in the direction you are facing)
- Start a game: Space or F12 (the console’s Reset switch)
- Save and load: Ctrl + 0–9 saves, Alt + 0–9 loads
There are no variations to choose, and the manual states that the difficulty and Select switches do nothing in this game.
Gameplay
You start at the bottom of the screen, and the six bases sit along the top, behind a thick layer of dirt that the manual calls a force field. You dig your own maze as you go. Two kinds of enemy tank guard the field. White sentry tanks can only use tunnels that already exist, while blue digger tanks carve their own. Either kind destroys you with a shot or by ramming you. You can shoot tanks back, but if you destroy both, a replacement soon arrives. A wrecked tank leaves debris you can drive through but cannot shoot through.
The clock is a third tank rolling along the bottom of the screen towards your spare capsules. If it reaches them before all six bases are gone, you lose a capsule. You begin with six (only three are shown at once) and earn one more after each level. The game has 12 levels of four rounds each. From level 2 the bases appear one at a time, and in some rounds there is almost no dirt at all, so the tanks come straight for you.
Scoring
Every tank is worth 50 points. Bases are worth more in later rounds, and much more if you have already dug up that round’s hidden supply item. Leftover time also pays: you get 40 points for each tick left on the timer when the last base falls.
| Hidden item | Points |
|---|---|
| Shovel | 1,000 |
| Walkie-talkie | 2,000 |
| Key | 3,000 |
| Flag | 4,000 |
Tips
- Find the item before the bases. It raises the value of every base you destroy afterwards, so it is usually the best source of points.
- Let the blue tanks dig for you. Lure a digger tank up near the bases and it will clear the dirt in front of them, while you stay out of its line of fire.
- Don’t shoot tanks for fun. They are only worth 50 points, and killing both just brings in a fresh one.
- Ambush from side tunnels. Wait in a passage that crosses a tank’s path and fire as it lines up with you.
History
Sega published several 2600 cartridges under its own name, including Tac-Scan and Star Trek, which Lorenz also worked on. Thunderground is based on the second stage of Borderline, in which enemies could only follow the path the player had cut. The 2600 game fits in 4 kilobytes. When Videogaming Illustrated reviewed it in December 1983, both reviewers saw it as a cousin of Dig Dug and Mr. Do!, even though Borderline came first, and both still rated it well. In Germany the same game was sold by the mail-order company Quelle as Phantompanzer II.
Similar games to play next
- Dig Dug – the tunnelling arcade game reviewers compared it to
- Mr. Do! – dig your own paths while monsters chase you
- Tac-Scan – another Sega space shooter programmed by Jeff Lorenz
- Sub-Scan – Sega’s 2600 submarine game from the same year
- Spy Hunter – a later Sega cartridge, also by Lorenz