It’s Muri time!
Many DOS games let you choose between PC speaker sound or MIDI and digital samples, which required a sound card. When dad got a Sound Blaster 16 we had to manually input the IRQ and DMA in setup programs for each game, though later games like Tyrian could autodetect the sound card.
Anyway, the PC speaker can only generate one fairly simple wave at a time, with no way to adjust the volume. For Muri I used a synth emulating the PC speaker, set up by Mattias, to generate these sounds. The game uses a priority system to make sure that only one sound is played at a time. A higher priority sound will overwrite a lower one, which works surprisingly well in practice!
Mattias also wrote two PC speaker songs for the game, but only one was used. The other was going to play in a cutscene, but was considered too distracting.
There’s at least one new enemy or boss in each of Muri’s 20 stages, ranging from small robots that don’t even notice you to jumping, ducking and dodging humanoids with rapid-fire rifles. Most robots come in four different colors with slightly different abilities, and each episode has a unique enemy that usually guards or carries something important.
Though most enemies are limited to simply running into you or firing slow-moving bullets in one of 8 directions, I hope I’ve managed to add enough variety to them. I noticed during testing that since you can jump on enemies from above to damage them, some testers tried to do this all the time, even if it meant crashing into them and dying more often than usual. :p
Pickups and weapons
Aside from the regular point bonuses, there are several energy pickups and one extra life more or less hidden in each stage. Both the energy and extra lives are replaced by point bonuses on higher difficulties.
Since all the enemies and bosses are defeated by simply shooting at them, the game could become too hard or too easy depending on your current weapons. To alleviate this, there’s a rare kind of pickup that gives you infinite ammo for a weapon, usually before a boss where I wouldn’t want the player to get stuck with just the regular gun. I also tried to make the weapons different enough from one another that they all had their uses, though as you’d expect they are more powerful the rarer they are.
The weapons got the DOS-y names RAPID, MKV, LASER, MEGA and CHAOS, with distinct sounds for each one. MKV stands for Mark Five, but this isn’t explained by the game. Letting the player guess at the meanings of weird acronyms is part of what I liked about old games. But now I’ve ruined it for you. Oh well.
Next up is story, vertical problems and teaching the player!