MidBoss is a graphical roguelike with a fixed isometric perspective. The game was first released as a free alpha on April 15, 2014.
The game takes place in a randomly generated dungeon with an unlimited number of floors. The player character can level up and increase their attributes by killing monsters and gaining experience. The character's natural form is the imp, but the player can possess defeated creatures and take on their form. While in another form killing monsters yields form experience used to level up the form and unlock that monster's abilities. If the player dies while in imp form the game ends and the player's saved game is deleted.
There are four meta attributes; violence, cruelty, adamancy and relentlessness. When the player levels up they can increase only these four attributes. The attributes used for determining health, damage, etc. are a result of multiplying these meta attributes by the attribute multiplier of the current form.
The base form, the imp, has only two abilities; Possess and Depossess. When possess is cast on a monster and that monster is killed, the player is prompted whether they want to possess that creature. Upon possessing the player moves into the creature's space and takes on their form. While in that form killing monsters yields form experience used to level up the form. Every level one new ability is unlocked until all abilities are unlocked and the form is considered mastered.
Equipping a form gives the player access to that form's selected abilities. Players can have 3 forms equipped at a time, 4 in imp form. One of these forms is always the imp form, giving the player the Possess and Depossess abilities. While in non-imp form the second is always the creature's current form. That means the player can equip 2 optional forms as an imp, or 1 when in any other form.