Some big battles took place at the Ypres salient during World War One, it's well known for the trenches. These battles are condensed in the solitaire Print and Play deckbuilder Wipers Salient, where you play as the allied forces - trying to survive the ever intensifying attacks of the German enemy.
Every time you play, you will fight the same battle. Which feels rather fitting for the theme. The build up of the enemy forces is predictable. Every card that comes out will be a little harder to beat. Every card will have an worse effect on the morale and the health of your troops.
Your starting hand has enough resources to buy a decent card, but the attack value is too low to beat the first enemy that comes into play. Your morale suffers. That's when the game starts for real.
Every turn one new enemy card comes into play. You can buy one new card from the market, then you must adjust the morale and health value of all cards in hand on your Disposition tracker (hopefully you'll recover some). You can now attack the enemy. Some cards will give you bonus actions. Then the remaining enemy cards attack. You lose the game once either morale or health reaches zero. You win if you can take out all enemy cards.
A lot is dependent on what cards are available on the market. You will lose this game to bad luck. You can only win by planning ahead and buying the right cards when they show up. Sometimes skip buying, sometimes buy a filler card to get more resources or restore health or morale. But it is a hard game to win. Again, feels very thematic.
A session takes 10-15 minutes, so you probably will want to try again right after your loss. Then lose again. It is not unwinnable though. Some cards have very powerful features. Like cards that let you put an enemy card back on its deck, cards that let you draw an extra card or cards that let you double the attack value of another card in your hand. If you manage to buy a selection of those, and not let your deck get too big, you stand a chance.
Today was my 20th play, and my third win. I really like this one as a filler game. The tension in some turns is great. The illustrations - all period artwork - help with immersion. Some are grim, but most have a light touch as well.