It's not easy being the only one of something but even worse is being the last.  The mushroom kingdom (a different one) was a sprawling underground empire once, but that time is long gone, and the only remnant is a single fungal explorer who'd been sleeping in the depths.  A message invaded Greencap's dreams, informing him he's the last of his kind, and to revive his people he'll need to reach the top of the world.  Something has gone wrong somewhere but it just might be fixable, if only Greencap can become nimble and strong enough to reach the end of the caverns.

Lone Fungus is a Metroidvania-styled adventure with a focus on platforming challenges, where every move adds a bit more to Greencap's ability to zip around the stages and explore new areas.  A dash move is obviously helpful in reaching tough platforms, especially seeing as it can be used both horizontally and vertically, but even the combat moves are designed not just to make it easier to beat on enemies but also have a secondary mobility function.

While initially Greencap can simply walk and jump, his moveset builds at a good pace.  The sword comes first, because there needs to be some way to deal with the enemies, and the lack of major air-time means the first areas can be focused on the basics.  The sword can swing forward or down, and the advantage of swinging down is that it lets Greencap bounce on enemies when it hits.  The downswing also works on spikes, and while it doesn't break them it does mean you can use the bounce to get over large pointy sections.  There is no upswing, though, justified by the fact that the mushroom's cap is just too big for that to be practical.

Soon after getting the sword the first mushmovers show up, at which point the platforming starts to come into focus.  Mushmovers are glowing green items you can smack with the sword for a bounce, some of which only give a little pop while others send Greencap flying in the direction of their arrows.  They're scattered liberally throughout every area in the game, especially in challenge rooms where bonus items are waiting at the end of fast-paced and unforgiving platforming gauntlets.  The challenge rooms offer rewards like new equippable items, secret ladybug collectibles, and other upgrades, but you'll have to earn them first.  None are required to beat the game, thankfully, but it's hard to walk away from a room knowing a little more care and experience will make it give up a tasty reward.  Fortunately there are no limits on lives and the thorns that line the walls of the challenge rooms will never take away that last point of health, so there's no drawback from beating on the jumping sequence time and time again until finally and triumphantly getting it right.

While the challenge rooms have good bonus upgrades to chase after, the main areas also have their share of secrets and jumping challenges with their own set of rewards.  One of the earliest abilities Greencap finds, for example, is a healing skill that uses thirty MP, and pickups that permanently add a single point to the MP gauge are fairly common.  The occasional spore pickup expands the number of gameplay-tweaking relics Greencap can equip at once, and the relics themselves range from "right out in the open if you can reach it" to "got lucky and stumbled across a hidden room".

The primary focus may be on platforming but the combat does have its own share of upgrades and modifiers.  Relics, magic, and other upgrades can effect how you approach beating on the many critters roaming the various biomes, and you can customize your mushroom's build depending on play style.  There's no rule saying you need to kill everything so zipping on by isn't going to leave resources behind, in which case speed and a few extra frames of post-damage invincibility would be the way to go.  Alternately a build focusing on magic recovery means you could cast to your heart's content while regaining magic by hitting enemies with the sword, and it has the added bonus of spells that make up for Greencap's inability to slash upwards.

Lone Fungus is off to a very strong start in its Early Access phase, with eight out of twelve areas in place and regular updates tweaking game mechanics and squashing bugs.  The combat is strong enough to act as a good supplement to the platforming, and there's a real challenge in exploring everywhere and collecting all the extra pickups.  There's a good balance in the world design between seeing the obvious way to go and chasing after secrets, and regular boss fights put all of Greencap's skills to the test.  Some of the more advanced platforming techniques take practice but when you've taught your fingers the right button order the mushroom can tear through the screens barely touching the ground.  It's hard to say what exactly a lost mushroom civilization would have gotten up to when it was more than a forgotten ruin deep below the surface, but Lone Fungus theorizes that it taught its people to fly.