Transformice is an independent multiplayer free-to-play online platform browser game created by French designers known by their aliases Melibellule and Tigrounette. Melibellule produces the game’s artwork and graphics, while Tigrounette programs the game’s functions and mechanics.
The main objective of the game is to collect a piece of cheese placed randomly around a map. Players control a mouse with the arrow keys, numeric keypad or the WASD keys to run, duck, jump and perform various techniques, such as wall jumping and corner jumping. Players mice must touch the cheese to collect it. After which, the player must take the collected cheese back to the map’s mouse hole to finish. The number of cheese and mouse holes varies between maps. Players are awarded points on a scoreboard that is updated in real-time.
Bonus points are awarded for players who place first, second or third. Collecting cheese is recorded into a player’s permanent stats. Players are also given extra recognition in their stats for finishing first. Maps have a time limit of two minutes, at which time a new map is loaded. Maps can instantly switch before the time limit if all mice complete the map or die. The timer will change to 20 seconds if the Shaman dies or too few mice are left on the map. Dying adds one point to a player’s score on the scoreboard.
When a player reaches the highest score on the scoreboard, they will become a Shaman in the next map involving one. The general objective of the Shaman is to help the other mice to reach the cheese and bring it back to the hole. Doing so will award the Shaman with “saves” for each mouse who completes the map, which are recorded onto the player’s profile. The Shaman can do so by summoning objects such as boards, boxes, anvils, spirit, and balloons to create buildings or contraptions such as bridges to cross gaps or various other obstacles. A shaman can ‘anchor’ or connect boards and boxes to other world objects or summoned objects with various-colored nails. Red nails keep an object firmly grounded and will not move, but it can rotate on the anchor. Yellow nails connect to most other objects, particularly red-nailed ones, and keep an object’s placement, but can move. Green nails connect two objects but are loose and can rotate an object.
Upon reaching 1,000 total saves as a Shaman, a player can choose to become a ‘hard mode’ Shaman. In hard mode, a Shaman cannot use red nails which anchor an object solidly, nor can they use the Spirit tool, which can push mice and objects with a flash of light. Spirit is the only object allowed to be cast outside of summoning range. In lieu of this, hard mode Shamans can create a pre-made ‘totem’, which is constructed on an in-game editor map. Totems can be constructed with up to 20 objects, but only one red nail may be used as an anchor. A completed totem construction can be summoned instantly as a hard mode Shaman and is immediately functional, but may only be summoned once per map.
Collected cheese is also saved up and used as currency in the game. Players can use this currency to buy virtual clothing items for their mouse in the game’s item shop. Items are purely visual and do not give bonus stats. Players can also create their own maps via an in-game editor. Created maps must be verified by a test run of the map where the creator has to be able to successfully collect the cheese and bring it back to the hole. Once verified, players can choose to submit their map into rotation at the cost of 40 cheese.
An in-game achievement system awards players with new titles. Titles are awarded for collecting specific numbers of cheese, obtaining a certain amount of first place victories, accumulating saves as a Shaman and buying items from the shop.
Trolling is considered a part of the game, as stated in the in-game ‘Help/Rules’ menu. Some players infrequently decide to troll, whether playing as the Shaman or a normal mouse. Shamans can kill other mice by striking them with cannonballs and other objects, as well as blocking them from progressing in the map by building a structure that is impossible to pass. Normal mice can troll by stalling, which is to stay on the map for as long as possible without capturing the cheese. Normal mice may also choose to push the Shaman’s buildings off the stage. In maps where there is collision detection, they can also push other mice, including the Shaman, off the stage.