The Experience Bar was a mechanic that was active indefinitely regardless of mode. It stayed below the space where player buffs are seen and couldn't be adjusted. It was used as Jetshift Mod's levelling system.
The bar consisted of a dark background bar, overlayed by a bar of which colour was associated with the biome the player was in (e.g. a red bar in Crimson, a blue bar in Hallow). It did not take colours from other modded biomes. Dependant on how much experience the player has, the overlaying bar would vary in size. If the bar filled up all the way to the end, the player would level up. The level number was seen right next to the Experience Bar.
Experience was earned by killing enemies and bosses. Each NPC would have given a certain amount of experience based on their max life.
Higher levels gave the player endless stat increases, with slightly increased damage (up to a maximum of 4), a defense increase of 2 (up to a maximum of 20), and 25 increased life (up to a maximum of 250). Due to the caps that were set on each parameter, every stat maxed out at level 10.
If the player died, the stats would have reset and the experience count went back to 0.