Health is not cumulative and resets itself for every level played directly after the previous one or if the player chooses to restart a level or quit the game.
If the main character can take more than one hit, its health will be indicated somewhere along the edge of the screen. For most Nitrome games with health indicators, this is displayed at the corner of the screen, on the left side.
Games such as Sandman and Scribble involving the use of multiple main characters at a time have their health determined by the number of characters the player starts out with. In some cases, there may be a minimal required number for characters that must reach the goal for a level to be successfully completed.
Games that make use of checkpoints generally have main characters that can only take one hit from an enemy or hazard. These games omit the health indicator from the screen, as the one hit results in the player restarting the level from the last checkpoint the main character passed, if any.
A main character's health starts out at maximum when a level commences, and decreases for every hazard or enemy hit. This is usually indicated by a change in colour of a character's health bar or the removal or change in physical appearance of an icon resembling a hit point. On average, a main character's health is limited to three hits, though these can vary based on the difficulty or frequency of checkpoints appearing during the course of the game.
When main characters take damage, they often enter a brief stun phase that allows them to become invincible and in some cases, move through hazards and enemies. A stun period is detectable when the main character takes a hit and flashes while on screen. The stun period is temporary and the main character becomes vulnerable to hazards and enemies once their image is solid.
At the point where an indicator shows full depletion, the character's death animation will be seen, forcing the player to restart the level or from the last checkpoint passed after the animation finishes. Some games, after the death animation, display a "Game Over" screen, providing players with the option of restarting (the entire level or the last checkpoint passed), submitting their highscores or returning to the main menu.
Games where the main character has only one hit of health usually do not bring up a "Game Over" screen and instead, use a screen transition (often a fade) to place the character at the start of the level or last checkpoint touched. In these games, players submit their highscores at the end of a successfully completed level or when the game is fully complete.
Enemies and bosses
Enemies and bosses that can be defeated have their health determined by the number of defined attacks the main character can successfully land on them to decrease it. Many bosses and some enemies have health indicators that show the approximate number of hits necessary to kill them. They, like main characters, also have a death animation to show when the player has defeated them.
Some Nitrome games with health indicators have pickups that can be obtained by the main character to replenish any health lost within a single level. A health indicator cannot exceed its maximum capacity, so if the main character is already at maximum health at the time of collecting, no effect takes place.
There are a few cases where health is replenished not through the form of a pickup.
In Blast RPG, the boy knight's health metre can be restored at any point in the game rather than having to wait for a pickup, so long as the player has the Heal item. This item can be purchased from the shopkeeper or sometimes collected in chests that are added to the in-game inventory. Clicking on the health item from the list of items displayed restores the boy knight's health to its fullness instantly. This can be done multiple times within a level, as long as the player has more than one Heal item. Unlike pickups, Heal can be carried on to the next stage of the game once it is in the inventory.
Health may also be added on with the collection of a power up crate, as is the case with Rainbogeddon, Nitrome's first release of 2012. When a powerup crate is picked up, it acts as a secondary health to the grey creatures' one-hit take. Contact with an enemy or a hazard while a powerup is active causes the grey creature to lose it. Although not referred to as "health" within the game, the temporary stun from losing the powerup allows the grey creatures to take one more hit before dying.
Health may also regenerate on its own once lost, without the need for a pickup. The only Nitrome game with a health metre fitting this characteristic is Canopy, at present. Once hit by a hazard or enemy, Canopy loses a third of its health, as indicated in its blue coloured metre. Over time, as long as the game remains unpaused, the lost health will replenish itself until the bar is fully blue. The main character, in this case, dies when its health take is depleted faster than the bar takes to increase to its full length. Any hits from hazardous objects or creatures will subtract points from the player's level score.