Building a Retro Linux Gaming Computer Part 44: The Legend of Kobo

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Continued from Part 43: Demons and Angels

A lot of early UNIX and therefore Linux games struggled with the fact that the X toolkit was geared towards constructing staid graphical user interfaces, rather than for the speed and flexibility needed by games. Both 100 Great Linux Games as well as the Linux Games & Entertainment for X Windows compilation included many valiant attempts, which while all being admirable in their own way, failed to sustain much in the way of scrutiny. One X11 game that does is Xkobo.

Inspired by Namco’s 1981 arcade title Bosconian, Xkobo was created by the Japanese coder Akira Higuchi and released for a diversity of different UNIX derived systems starting in 1995. The original source code tarball archive of the final 1.11 version from 1997 has build issues when trying to do so on newer versions of Linux, forcing me to use an older compiled binary from 1998 instead included in the xkobo-1.11-1.i386.rpm package to play the game.

For an X11 based game, Xkobo is remarkable in how smooth and fast it is to play. While having the expected limitation of being restricted to a small game window, the art itself is polished and the scrolling seamless. I am often not enamoured by "shmups" in this style, but the puzzle element here of tactically dismantling the enemy fortresses by targeting the coloured nodes helped to keep me engaged, at least until the game descends too close to being bullet hell.

Even then, Xkobo does mercifully allow you to start over from the stage after the one you last cleared when your lives run out. This means you can tackle the game in bursts, as Xkobo would wear out its welcome if it forced you to solve it all in one sitting. There are 50 stages to the game, although I have only cleared 22 of them so far myself. For those without the patience, you can also play through any stage with infinite lives through the use of the "-cheat" launch flag.

There is also a "-doublesize" flag that increases the size of the game window at the cost of using much more memory, but with 512 MB of RAM installed in my machine, I can go ahead and laugh in the face of danger. Even on my overpowered for the time computer however, the game will still slow down if a lot of explosions are drawn on screen at the same time. This can be further mitigated through the use of "-fast" flag, which again consumes more memory in exchange for a faster algorithm.

A modified branch of Xkobo by Kenneth Nielsen also exists which fixes the game to build with the new strong type checking found in later compilers; Nielsen would later merge this with a fork by Wolfgang Jährling which adds some new levels and enemies to the game. This formed the basis of the RPM packages distributed by Dag Wieers for use on later Red Hat Linux and Fedora releases, with most players likely completely unaware there had ever been any changes.

A separate fork of Xkobo by Masanao Izumo was also developed which added sound effects to the game, work which would later be built upon by David Olofson to craft Kobo Deluxe starting in 2001. This reworked Xkobo to use SDL as well as further modernizing the game. I was unable to get any version of Kobo Deluxe past 0.4.1 to compile on Red Hat Linux 7.3, which was when the game engine switched to OpenGL being loaded dynamically, but any version before that works.

Work on Kobo Deluxe continued past 2007, and the game can still be found packaged with many modern Linux distributions, but David Olofson himself has moved on to other projects. One of these was his more experimental Kobo II prototype, which eventually lead to the release of Kobo Redux in 2017. This is still available for purchase from itch.io, although further updates have stalled due to life and health challenges on the part of Olofson.

The more I played these expanded versions of the game though, for all of their bells and whistles, I could not help but feel that sometimes less is more. The original Xkobo is a great example of what can be done when you focus on just the core gameplay loop paired with a consistent set of art assets. It may seem simple when put against the variety of game modes and explosion of effects offered by its inheritors, but there is an elegance here that still shines through after all of these years.

There is a reason why SDL and SVGAlib, and to a lesser extent GGI and Allegro, were embraced by Linux game developers. Magic can come out of people working against imposed limitations however, and games like Xkobo succeed by this. This is not to say that a bit of pizzazz is always unwelcome, especially when you have your own multimedia toolkit to promote and the beer of your sponsor to sell. It is time for us to cut to commercial.

Carrying on in Part 45: Promotional Offer

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