The first thing you’ll notice about “Lips,” the Xbox 360’s answer to the PlayStation consoles’ venerable “SingStar” franchise, is its two wireless, motion-sensitive microphones that flash all sorts of crazy colors while you sing. These things are magnificent, a triumph of industrial design. They’re sturdy, eye-catching, highly functional and, most of all, fun. They should become the default input device for all present and future Xbox 360 games featuring singing. (Right now, they only work on “Lips,” but Harmonix is reportedly working on a patch to make them compatible with its “Rock Band 2.”)

The microphones are a hit, but “Lips” the game (rated T, $70 on Xbox 360 for the game and two microphones), from iNiS, is clearly the first game in a planned franchise. For everything it does right, there’s another area in which it comes up short.

Take the much-touted feature that lets you add your own songs from either your 360’s hard drive or a USB-enabled MP3 player. In theory, it’s fantastic that I can sing along to Sonic Youth’s “Kissability” because there’s no way that song would ever show up in a karaoke game. On the other hand, though, you pretty much have to know all the words ahead of time. For obvious reasons, lyrics for songs you add to the game yourself don’t appear. You just sing along, making “Lips” a great tool for teaching you that you don’t have a clue what half your favorite songs’ words are. That’s fine, and basically what I expected, but the game struggles to recognize what parts of the song are singing and what parts are musical instruments. I was able to rack up points singing nonsense along with the instrumental stretch at the end of New Young Pony Club’s “Ice Cream,” below, which sadly is not in the game.

About 40 songs ship with the game. Considering that’s half the number of tracks you’ll find in the newest “Rock Band” or “Guitar Hero” titles, the selection is both wide-ranging and eclectic. It’s got Rihanna and Taylor Swift, as well as Depeche Mode and John Denver. All of the songs on the disc feature music videos, most of them the originals. (My wife and I got a kick out of watching Freddie Mercury preen around stage during “Another One Bites the Dust.” How could anyone have been surprised to find out he was gay?)

Getting all the videos is cool, especially because a lot of these sell on iTunes for $2 a pop, but be warned they’re not in high definition. While I wouldn’t expect Johnny Cash’s “Ring of Fire” in HD, surely there’s a better quality version of the video for Lil Mama’s “Lip Gloss” than what appears on “Lips.”

Once you fire up a song and start singing, some of these concerns fade into the background. The game’s lyrical and pitch cues are easy to grasp and understand. Words appear on the screen, and a bouncing ball tells you when to sing. You might struggle with unfamiliar songs, as “Lips” doesn’t display as many words at a time as other singing games. But the game’s grading is based more on pitch, with bonus points awarded for vibrato, than it is on getting the words right.

The motion-sensitive mics add a new wrinkle. From time to time, the game will cue you to strike a pose, such as tipping the mic (and presumably your head) back. These gestures are a great way to get you moving and make you feel like a performer, but they’re not always integrated into the game as well as they could be. Some of the gestures require you to move the mic away from your lips. If you’re prompted to perform a gesture, you’ll be stuck trying to decide whether it’s more important to execute the gesture or hit all the notes.

The inclusion of two mics lets players sing in co-op or versus mode, and there are some goofy little minigames you can play, too. One features the two players trying to sing well enough in sync to make an animated couple kiss. As you nail your lines, the pair get closer and closer, with the game requiring the two of you to synchronize a gesture to follow through on the smooch. It’s pretty corny, and I can’t imagine playing it more than enough times to get the achievement points the game awards for doing it well.

Unlike party games like “Rock Band 2” and “Guitar Hero: World Tour” that feature singing, you can’t flunk out of a song in “Lips.” While music game rookies and horrible showertime warblers will appreciate this, the game is too easy. It’s one thing not to fail, but I scored 767,624 points, good enough for a “star” rating by rubbing the microphone on fabric for the entirety of Leona Lewis’ forgettable “Bleeding Love,” a test I admittedly did not come up with on my own. (I did stop generating friction long enough to perform all the mic gestures, but I didn’t sing a note.) In a similar vein, reading my friend Mike Murphy’s excellent Press Democrat blog post on Conan O’Brien aloud during Avril Lavigne’s “Complicated” netted me 420,108, good enough for a “planet” rating. (Sorry, Murph. “Lips” just liked the sound of fabric better.)

Despite this litany of misgivings, “Lips” has a certain charm. My wife and I typically switch back and forth on vocals whenever we play “Rock Band 2,” but this game lets us democratically go at the same time. The ability to add your own music, despite its flaws, comes in handy, and most of the 40 songs should go over great at a party. (The original video for a-Ha’s “Take On Me,” which doesn’t appear on YouTube or I’d embed it, is easily the game’s highlight.)

Until “Rock Band 2” adds support for the light-up mics, the $70-for-40-songs-and-two-mics price tag makes the game a moderately tough sell for anyone but karaoke die-hards, but that doesn’t mean it’s not worth keeping your eye out for a sale or price drop. Basically, this is a game that does enough things right that if there’s a “Lips 2,” there’ll be plenty worth getting excited about. Microsoft is supporting “Lips” with downloadable songs, but the selection thus far has been somewhat lackluster. (Hint: There’s only one Men at Work song anyone wants to sing, and it isn’t “Be Good Johnny.”) So long as iNiS takes its cues from Harmonix and makes songs and videos from this game compatible with any new “Lips” offering, the franchise is going somewhere good. It’s just not quite there yet.

In case you’re curious, the song list follows. In an attempt to show off my versatility, I’ve put six favorites in bold.

a-ha – “Take on Me”
Nirvana – “In Bloom”
Alicia Keys – “No One”
Peter Bjorn and John – “Young Folks”
Aly & AJ – “Potential Break Up Song”
Queen – “Another One Bites the Dust”
Avril Lavigne – “Complicated”
R.E.M. – “The One I Love”
Ben E. King – “Stand by Me”

Radiohead – “Fake Plastic Trees”

Beyoncé – “Irreplaceable”
The Ramones – “I Wanna Be Sedated”

Blondie – “Call Me”

Rascal Flatts – “Stand”
Chris Brown – “With You”
Rihanna – “Umbrella”
Coldplay – “Yellow”
Roxette – “Listen to Your Heart”
Depeche Mode – “Personal Jesus”
Sara Bareilles – “Love Song”
Destiny’s Child – “Survivor”
Sheryl Crow – “Soak Up the Sun”
Dido – “White Flag”
Taylor Swift – “I’m Only Me When I’m With You”
Duffy – “Mercy”
The Bangles – “Walk Like an Egyptian”
Duran Duran – “Hungry Like the Wolf”
The Fray – “Over My Head (Cable Car)”
John Denver – “Take Me Home, Country Roads”
The Jackson 5 – “ABC”

Johnny Cash – “Ring of Fire”

The Police – “Every Little Thing She Does Is Magic”
Leona Lewis – “Bleeding Love”
The Raveonettes – “Love in a Trashcan”

Lil’ Mama – “Lip Gloss”

Trace Adkins – “Ladies Love Country Boys”
Lupe Fiasco (featuring Matthew Santos) – “Superstar”
Weezer – “Island in the Sun”
Maroon 5 – “Makes Me Wonder”

Young MC – “Bust a Move”