I can tell you exactly when it happened: My roommate and I booted up Gaseous Exposure, the first level to feature gas. No tutorial window popped up, no warning klaxons blared. Just: Here's some gas. Figure it out.

We slowly nosed our ships into it, unsure whether it would harm us, ready to spin around at a moment's notice and beeline to the nearest pool of water. Once we found out that we could fly through it unhurt, we tried to figure out how we could manipulate the gas to our advantage. What would happen if we shot a rocket into it? What if it engulfed a wayward scientist we needed to rescue? How about we shoot that destructible rock so that lava pours--

"Ooooh," I said to my roommate. "That's what the gas does."

At that moment, I realized why PixelJunk Shooter has me hooked: No other game in recent memory has so easily captured the joy of discovery.

In many ways PixelJunk Shooter brings to mind classic NES games that taught you how to play by showing, not telling. Consider the opening moments of Super Mario Bros.: A Goomba marches inexorably towards Mario. You instinctively know that running into this thing is bad, so you blindly hit a button. Mario leaps to safety, and you realize that you can avoid enemies by jumping.

But maybe you mistime your jump and land square on that Goomba's head. "Hey!" you exclaim. "I can stomp on these dudes!"

Just like that, you've learned the key components of the game, without any glaring messages telling you to "Press A to jump" or "Hop on enemies to kill them."

PixelJunk Shooter adheres to this show-not-tell philosophy, dropping few in-game hints. Like the gas my roommate and I encountered, most new elements are simply introduced, and you've got to your own brainpower to figure out how they work in the game world. Thankfully, most of them operate according to real-world principles and can be easily puzzled out. For example, shoot water at lava and it hardens to stone, or blast lava at ice to make it melt.

Likewise, when you obtain an upgrade for your ship, the game excitedly informs you of its name ("Magma Suit!!"), but that's the only hint you'll get. It's up to you to piece together how you can use that upgrade to get you through the level.

One trick I learned completely by chance -- I couldn't find documentation of it anywhere in the game. While waiting out a bathroom break for my roommate, I absentmindedly twirled the analog stick in a circle. My ship did a little spin and made a hissing noise. I found it cool but seemingly useless, and when we got back to playing we'd do it whenever we had time to kill waiting for the other player to catch up. Then one of us did it next to a chunk of destructible rock, and suddenly the spin move made sense.

Moments like that have elevated PixelJunk Shooter to my top echelon of games released this year. I could name other instances, but I don't want to spoil the joy of discovery for you. Go play the game and figure them out for yourself.