There will likely be a few new enemies. Here are a few ideas:
Fire Mouse I plan on this enemy running away from the player (at a slow speed) or running around randomly while periodically spawning slow-moving fireballs. These fireballs are homing and fizzle out with time or upon collision with a wall or other object. Interestingly, while the Fire Mouse can harm the players, it can only singe, not truly start a fire, which is why the trees do not catch fire. My only worry with this character is that it resembles Bippo quite a bit. The below is probably not the finished model. There will likely be modifications.
Will-O’-Wisp: These resemble balls of light, but are somewhat difficult to see. They slowly chase after the character. These balls, upon their destruction, trigger a random linedef between 1001-1008 (in short, somewhat random effects dependent on the stage). Alternatively, I may have them spawn an enemy sometimes in addition to triggering linedefs. Depending on the stage, the effects of these balls of light range from beneficial to downright nasty. More often the former, so you are sometimes best off trying to avoid them.
Wisp Master: A larger Will-O’-Wisp that will summon normal ones, as well as fireballs (much akin to the Fire Mouse). This will likely be a boss, or at least a rather tough enemy. I am considering making him turn red when he is low on health, and only then will he summon fireballs.
Flame Master: Either a ball of flame or an oddly-colored flame, possibly both. This enemy will spawn fireballs. Unfortunately, since this enemy is made of fire, the elemental shield is a must if you want to kill it unscathed. Otherwise, it is best to run. Flame Masters do not move.
Enraged Spirits: It seems Galto is not the only spirit from the Battle of Crécy to have come into Mobius. Others seem to have come here as well. Unfortunately, Galto is the only one who seems to have retained his sanity. These spirits are red and go into a semi-spindashing state periodically (during which time, they gain the Fire tag). They can float and take two hits.
More, mayhaps, later.