We featured Wren Games' Assembly on Board's Eye View just over a year ago. Like Assembly, Sensor Ghosts is also designed by Janice & Stu Turner: it's a standalone solo or co-operative 2–4 player sequel to their earlier game. Thematically, it takes over from where Assembly ends but there's no requirement to have played the previous game before you play this one.
For Sensor Ghosts, the premise is that you've now escaped the virus-ridden space station that was under the control of a psychopathic AI. You're trying to wend your way back to Earth in a space ship. Unfortunately, your route means flying through an asteroid field: a randomised 5x7 grid of sector cards, each of which is two-sided... You also have to find and bring back a sample of the virus (just two or three of the five face down tokens will be virus samples). You have shields that protect you from an asteroid impact but hitting an asteroid will deplete your shields. Hit an asteroid (yellow sector card) with shields down and it's kaput. If you hit an obstructed sector (red card) or fly off the edge of the grid your ship is destroyed regardless of the state of your shields. Green cards are safe and purple cards boost you on your way - continuing your movement in the direction in which you were traveling. Boost cards can therefore be very helpful but, equally, they can rocket you into oblivion. The asteroid field isn't static or stable: at the end of every turn you'll be shifting the row ahead of the ship and flipping cards in the row two ahead of your ship...
You traverse the asteroid field by playing command cards from your hand of three cards if playing solo or just two if playing as a co-op game. Fly cards allow you to move, but orientation is important because you'll ordinarily move in the direction of the Fly card that tops the discard pile. Alternatively, Fly cards can be used to peek at the reverse side of the three adjacent cards in the direction you select to play your card. Changing direction of movement requires you to discard two Fly cards to overcome the inertia but, playing as a co-op, you can ask other players to contribute from their hand. Scan cards allow you to flip a single sector card or, alternatively, allow you to shift a row of sector cards to the left.
Each player has a character card that gives them a helpful special ability, and each of these changes up the game, so you'll have fun trying each of them out. Your command cards are a finite commodity, however. It's a slim deck that you'll shuffle and recycle just once. After that, it's game over if you run out of cards before you get back to Earth with a virus sample. When the pressure mounts, that means you may just be tempted to take a chance and fly blind...
Sensor Ghosts can be a fiendishly tough puzzle game with a strong Pelmanism element. The game comes with a few cubes you can try to use to remind yourself of the location of sector cards with helpful reverse sides or to mark off sector cards you need to avoid at all costs but, be in no doubt, you'll need a good memory to beat this game. There's a helpful tension seeing your command deck run down, knowing that it effectively doubles as a timer, and you'll feel the pain any time you have to burn through your precious command cards in order to treat one of them as a 'wild' (which requires players to collectively discard three cards).
The game incorporates options for scaling up the difficulty and it incorporates a couple of variants, both of which make it harder still. Sensor Ghosts is at its best as a solo game and a two-player game using limited communication (don't show or tell each other exactly what command cards you have in your hand). Our one gripe was that it can be quite fiddly picking up, flipping and sliding along the sector cards every turn so we'd always recommend setting the cards out on a suitable neoprene mat.
Wren Games should be particularly commended for coming up with a sequel that continues the saga but which doesn't just give us more of the same. And since we're all thinking a lot about viruses right now, we're wondering if there might be a third instalment due that continues the story of what happens after the Sensor Ghosts players get the virus sample to Earth...