Unheart

Unheart is a Boulder Dash variant with deeper focus on puzzle solving than the original game.

The goal is to collect all hearts to open the exit to the next level. As a little dwarf you can dig holes in certain areas. Rocks are falling down if there is a free field below them, which can cause chain reactions like in the original game. The player's avatar can push stones or grenades horizontally. Each of the 69 levels is presented on a single screen.

There are some special items in the levels: grenades explode if they fall on rock or a rock is falling on them, but remain intact if falling on removable ground. When they explode, walls and rocks around the grenade are destroyed, potentially opening previously inaccessible areas. Balloons move up if there is a free field above them. They can transport rocks, grenades or the player upwards. The last special are conveyors which are only passable in one direction.

Without any nasties or other self-moving things populating the levels and with the tricky nature of the special stones the game's pushing and thinking outside the box puzzles are also influenced by Sokoban. The player can instantly restart the level, which is badly required, as the difficulty of the game is very high. There is no limitation on the retries, and even if a time counter is ticking, no time limit is given. The player can freely skip levels without any cheat.