If you're looking for manga similar to Shikei Game, you might like these titles.
On what seems to be a normal day, Arata and 33 of his classmates head to third period, where they find blank crossword puzzles on the desks. Suddenly, a mysterious being named Kuro appears, and within minutes countless students explode or are eviscerated in increasingly gory ways. The remaining survivors must use their smarts and their wits to survive the Dead Word Puzzle.
Partake in the horror, the terror, the bloodcurdling madness of the serial killer mind, and the one who dares exterminate them!
Takahata Shun's day at high school begins just as normal and boring as ever, but it doesn't end that way. After his teacher's head explodes, he and his classmates find themselves forced to play children's games, such as Daruma ga Koronda (a game like Red Light/Green Light), with deadly stakes. With no idea who is behind this mysterious deadly game session, and no way of knowing when it will finally end, the only thing Shun and other students can do is keep trying to win...
You can't leave this island until you've killed 100 people. The most deadly survival game begins on a solitary island where desires swirl and only the strongest survive!
Asahi and her friend Yamato are aboard a luxurious ocean liner for an unusual reason: the entertainment company Sky Nova invited them to be exclusive test players for a new game they've developed, and they must come as a pair. Joined by a handful of others such as a popular school idol and a suicidal boy, the duo eagerly awaits the beginning of the fun. However, what greets the teens is something far more sinister - a one way trip to a deserted island where they're forced to avoid traps, escape being hunted, and live to survive another day...
"Survival of the fittest" is a universal truth, one that Toma learns the hard way outside of the classroom. Chosen to fight on behalf of the Earth in an interplanetary tournament, Toma realizes that the loser will end up as dead meat--literally. According to the universal plan, there will be "Feeders" and there will be "Food," with the beings of one world feeding on the blood and meat of others. Only one planet can survive....Who will be on the menu?
Masahiko Mariyama, a small-time businessman, lives a modest life with his wife, two children, and dementia-stricken mother. Then one day, the people disappeared from the town! In the midst of his confusion, he is summoned to a place where he finds seven families and giant dolls. And so begins a compulsory recreational activity. No one is allowed to escape, and the winner will receive a luxurious prize, while the last place winner will be punished. One of them is sacrificed at a family meeting!
Out of nowhere, 99 girls were sent to a large room, where they are inadvertently transferred to the other side of the screen. There, strange creatures live, which begin to hunt the girls who cross the monitor.