Red Volcano Zone

The Red Volcano is the sixth Zone of SRB2. It first appeared in 1.09.4 as a secret and now has a complete First Act. A proof-of-concept second Act appeared in 2.0.

Overview
Red Volcano is set inside an icy, presumably dormant volcano's magma chambers. The main hazard is lava and the Unidus is present as an enemy here.

Acts
A medium-hard level which is rather short. Lava is present as the main hazard and a variety of gimmicks revolve around lava variants such as rising and falling lava and Lava Bubbles. The Unidus is the only enemy here and a secret outside area with a Token appears.

Secret Acts
A secret Christmas-themed level which appeared in 2.0 as a proof-of-concept Zone. The second Act of Red Volcano was originally meant to be an ice level. It is only a right turn, three Rings and a secret No Sonic ledge with a 1UP in it. The Zone had a crater at the start to represent exiting its magma chambers and was inaccessible by normal means.

Main things
Lava is everywhere here and will kill you very quickly if you aren't careful. The Unidus enemy is also extremely precise with its slow shots and is often placed where it can knock you into lava or distract you. The Lava Bubbles are the least of your worries but are still deadly. Blue Mountain Zone 2 isn't in the game anymore.

Statistics
Enemies:

Unidus, Lava Bubble

Hazards:

Lava, Springs, Bottomless Pits, Crushers

Things introduced:

Lava, Flame Jets, Whirlwind Shield-necessary areas

Emerald Tokens: Three (three in Act 1)

Acts: One

Status: Incomplete

Trivia

 * Blue Mountain Zone 2 was originally going to be the second Act (just more complete) but was dropped in favor of a regular lava-themed act.
 * Blue Mountain Zone 2 was the only inaccessible Zone (by normal means) in 2.0.
 * In 2.0, turning on "devmode" and typing in "map map17" would take you to Blue Mountain Zone 2.
 * The Lava Bubble is a Mario Mode enemy which is now unused in 2.1 in Mario Mode due to the lack of a castle area. This is now the only level in which it is used.
 * This Zone has the most differences from 2.0 to 2.1.
 * 2.0 RVZ1 did not have any Unidi and had a super-shortcut on the upper path. It is now an area with three Ring Monitors and a Force Shield.
 * 2.0 RVZ1 did not have an outside area in the act either.
 * The outside area was introduced in 2.1.6 as an easter egg and was remade in 2.1.7 along with replacing the GFZ sky with the CEZ sky.
 * This Zone has almost no point if you have an Elemental Shield.