Altus 24 is a game about an angel participating in a ceremonial ritual that involves ascending several giant towers, conquering the bosses on each of their roofs. The game cycles continuously between three "phases": Build, Spawn, and Action. In the build phase, you have access to an inventory of building items which you can use to construct platforms and mechanisms to help you scale further up the tower. After each build phase, new enemies spawn into the tower. Finally, in the action phase, the game unfreezes itself, and you are given 15 seconds to achieve as much as you can. This includes climbing higher, fighting enemies, and opening treasure chests. The latter two provide you with cards, which can be flipped over during the build phase, awarding you with random building blocks, potions, new weapons, upgrades, and other helpful items.