Irem is a legend in the shoot-'em-up genre. Known primarily for the R-Type series, the Japanese studio experimented with many different shooter mechanics, art styles, and orientations in arcades during the 1980s and 90s. Three of those experiments are available in Irem Collection Volume 1, the first of five planned installments published by ININ. All three are interesting in one way or another, and elevated by the quality-of-life features available in the compilation.

The first game is Image Fight, a vertically-scrolling arcade shooter from 1988 — a year after the launch of R-Type. Image Fight includes a few engaging twists that help it stand out from the crowd. As you move forward through each level, you'll pick up pods, which attach to the sides and back of your ship. If you pick up a blue pod, it will add to your forward firepower; if you pick up an orange pod, however, it will enhance your multi-directional attack options. Orange pods fire in the direction opposite of your movement, so you could move parallel to an enemy ship and blast it from the side, or retreat to a corner and fire diagonally. In addition, you can launch your port and starboard pods forward in a boomerang-like motion to pummel enemies. This adds a lot of tactical depth to what is, otherwise, a fairly standard space shoot-'em-up.

Luckily for collectors, Image Fight arrives in the collection with several variations. These cover the international and Japanese arcade versions of the game, plus NES, Famicom, and PC Engine ports. None of these eclipse the arcade originals, but they're great to have regardless.

The second game in Irem Collection Volume 1 is Image Fight II, a PC Engine exclusive from 1992. What makes Image Fight II so special is its presentation. It boasts fully-voiced animated cut-scenes between levels, which make the game feel like part shoot-'em-up and part anime. It's really something to see. Unfortunately, the dialogue is in Japanese, and developer Tozai Games has not introduced subtitles. Also unfortunate: the game is preposterously difficult. Part of the steep difficulty is due to powerful enemies that take multiple hits to dispatch, along with a stingy checkpoint system, but another part of it is due to the screen ratio. Image Fight II retains the original game's vertically-scrolling setup, but does so according to the limitations of a horizontal television screen. The result is a cramped layout where it's challenging to escape enemy projectiles. The PC Engine port of Image Fight suffers from this same problem.

The third, and best, game in the collection is X-Multiply, an arcade title from 1989. With its horizontally-scrolling gameplay and biological horrors, it feels like an outlier in this first volume. Luckily, it's the most accessible and forgiving of the bunch. It's also the weirdest. You'll fly a microscopic ship through a human body, fighting parasites inspired by the designs of H.R. Giger. It's like Fantastic Voyage meets Alien. On a mechanical level it's also strange, due to tentacles that sprout from the top and bottom of your ship. These not only fire projectiles, but they also damage enemies on contact and absorb bullets. The tentacles behave similarly to pods in Image Fight and its sequel: they move opposite to your ship's direction.

One thing to note for co-op enthusiasts out there: none of the games in the collection support simultaneous multiplayer, although Image Fight and X-Multiply allow two players to alternate back and forth.

Apart from the three main games and a handful of ports and variations, all of which appear expertly emulated, Irem Collection Volume 1 comes with the bells and whistles typical of shoot-'em-up compilations: rewind, save states, online leaderboards, difficulty settings, and button mapping. It also hosts some great screen filter and aspect ratio options, although rather paltry wallpaper choices.

Its best feature, though, is "stick aim", which allows player to control pods and tentacles with the right analog stick. This is a total game-changer and makes each title in the collection far more approachable. It almost transforms them into twin-stick shooters. If you're a purist, no worries: you can always deactivate this feature and play the game as the original Irem developers intended.

While Irem Collection Volume 1 sports quite a few quality-of-life elements, it sadly lacks special bonuses. You won't find any concept art, music players, trivia, or digitized box art & manuals here. You also won't find any instructions about how to play the games, including information on power-ups, enemies, and strategies. All three games have many moving parts — figuratively and literally — and it's not obvious at first how to play each one properly.

Irem Collection Volume 1 is a decent start to ININ's five-part anthology. While Image Fight II is too cramped and far too difficult, the original Image Fight and X-Multiply stand as solid entries in the Irem canon. What's more, everything is made easier and more accessible thanks to quality-of-life upgrades, including the game-changing "stick aim". Had Tozai gone the extra mile by including instructions, special features, and an English translation for Image Fight II, things could have been even better.