StepMania

StepMania is a free Pump It Up and Dance Dance Revolution simulator for any operating system. The unique thing about it is that it's fully customizable, from the theme setup to the notes during gameplay to even the game's metrics. The one thing that gets people playing is the fact that any song can be put into the game and be playable, but sometimes this doesn't work out so well. Since the notechart for each song has to be made first before playing it, unless one goes online and looks for simfiles, downloads them and puts them on the game, and then you have to hope that the simfile is good. Then there's graphics...

There's also two ways to play Stepmania. Either Pad (like how one would play DDR) or Keyboard, KB for short (like how one would play other rhythm games like Beatmania or Keyboardmania). Keyboard style is much more accessible and easier to play, but the learning curve is rather sharper than other rhythm games.

Currently, there's dozens of websites for the game and three games made off of it: In the Groove, Mungyodance, and Pump It Up Pro.

The latest version, StepMania 5 Alpha 1, can be downloaded from Google Code.

Tropes associated with this game are as follows:

 * Announcer Chatter: Only if the player wishes it via packs.
 * Ascended Glitch: The infamous "negative BPM" bug which could be exploited to cause "warps" in a chart, which could be used for all sorts of interesting effects. The 4.0 branch unfortunately fixed this bug, but the fork sm-ssc (later merged back in as "Step Mania 5") adds a new element called a "Warp" (along with "fake" arrows) which can be used for emulating this behavior in a more future-proof manner.
 * Gameplay Automation: Autoplay hits all arrows perfectly, but disqualifies you from making new records. Used when you want to see a stepchart without having to play it.
 * Stepmania 3.95, OpenITG, and beyond allows AutoplayCPU to be accessed during normal gameplay (other versions are used for demo only). This allows score records to be made. Furthermore, it is possible to set AutoplayCPU to perform 100% Marvelous/Fantastics by modifying AI.ini.
 * Harder Than Hard: Default names for each difficulty level, from hardest to easiest, are: Challenge > Hard > Medium > Easy > Beginner with Edit charts usually being harder than Challenge.
 * Justice. For reference, the difficulty right below it shrinks the timing window down to 1/3 their normal size. Justice shrinks it down to 1/5th normal timing window, leaving a timing window of +/- 0.036 of a second to get anything other than a miss. It also makes it to where if you lift your foot off the pad during a freeze note (or hit a roll), you will automatically drop the note. Judgerank 8 is bearable, Justice is considered impossible by all but a select few that get shunned on every community.
 * High Hopes, Zero Talent: It takes some skill to play the game. Then again, even if you can play the game extremely well, it takes some talent to actually make a good stepchart yourself. The reason why so many charts are terrible probably starts here when people don't realize this.
 * Small Name, Big Ego: Of course it rebounded the other way, with people that could step simfiles really well (at least not the DDR-like ones) becoming elitist. As of late the KB community is recovering from this and is doing a decent job.
 * Level Editor: Technically the game doesn't come with any songs, but the Stepmania disc does come with a batch of simfiles and the official Stepmixes.
 * Life Meter
 * Lost Forever: Simfile archives commonly get formatted like it's going out of style. So if you think you can just upload a simfile online and think it's safe, think again.
 * Luck-Based Mission: The Shuffle and Super Shuffle modifiers. Also present in In the Groove.
 * The RandomVanish mod. How does it work? It's an appearance mod that makes arrows disappear towards the center of the screen; when they come back 2 beats later, they're Shuffled.
 * Nintendo Hard: There's a reason that StepMania and sadomasochism have the same initials.
 * On a pad: During the last few years the definition of "paddable" has hyperinflated with the rise of new, better and better players. Mad Matt has passed an 18 footer. Even 16 steps per second isn't all that fast for the best.
 * On a keyboard: Any simfile by NVLM_ZK. These go up to 19 feet.
 * Speaking of keyboard charts, every "Vibrajacking" pack is hard. The difficulties start at 10 and a select few go up to 23!
 * Retraux: Using a theme from a classic Dance Dance Revolution version.
 * Sturgeon's Law: Jesus Christ on a stick... For the following reasons:
 * People don't offset the music, meaning a note that is "right on" is really off by some fraction of a beat.
 * The wrong BPM is used. Even if you're off by 0.1 BPM, it's enough to throw the song off before a minute is up.
 * Annoying patterns. Mashing a button/arrow down at 4 times the BPM of the song is not fun.
 * Or just haphazardly throw in a bunch of arrows for no rhyme or reason, because making the song harder is better than making it fun.
 * The Anime of the Game: A collaboration between Chris Danford, the creator, and Uno Shino, an upcoming anime artist. Seriously.
 * Trial and Error Gameplay: X-mod unfriendly gimmicks can quickly turn a song into a complete mess if you haven't seen the crazy gimmicks (MacGravel's Mellan and r21 Freak's Silikon really stand out in this regard).
 * Unwinnable By Design: Hentai Sweedevibe, Dear Arch and Right Type of Mood among other simfiles, whether they are designed to be either awful on purpose or just plain awful (see Sturgeon's Law).
 * And not even perfect AutoplayCPU could pass Dear Arch.