When you utter the name "Rygar", many people will instantly think of the NES game with the same name. In it, you played as the bare-chested warrior Rygar, making his way through both side-scrolling and overhead stages using his unique weapon, the Diskarmor, to take out hordes of enemies and defeat evil. Like most NES classics, though, it has its origins in the arcade, and appropriately Tecmo has chosen to release said version first.
The basic plot is still the same: as Rygar, you must traverse multiple levels and defeat hundreds of enemies to eventually vanquish their leader and bring peace back to the lands. Your main tool of destruction is the Diskarmor, essentially a spiked shield attached to a string, which Rygar can throw into enemies and then pull back, and he can also spin it over his head from front to back if he's surrounded. Rygar's secondary form of attack is far more standard for videogames: jumping on enemies can temporarily stun them, although a later upgrade gives you deadly jumps instead.
The arcade version of Rygar has absolutely no overhead stages. It's a side-scrolling only affair, although there are a few vertical sections here and there. All levels are connected without loading screens, instead rooms in which your score is tallied, which basically means you're running from the beginning to the end in one almost completely straight line with pretty much no interruptions. There's 27 levels total, so Rygar has quite a trek ahead of him!
Being an arcade game, Rygar is mercilessly hard: enemies will come at you in groups of three or four at a time and will not hesitate to jump or attack at unexpected times, aside from simply running straight at you. The enemies will also not only appear in front of you, but also behind, above, and even under you, so you have to be alert at all times or risk death. Like many other arcade games, a single hit will take you out, unless you're under the effect of a (very rare) invincibility item.
Thankfully, Rygar can find a few helpful upgrades by defeating enemies and smashing open special stones that pop up. One increases the length of the Diskarmor's string, while another gives it the ability to go straight through multiple enemies instead of "bouncing" off the first one it hits. In total there's five upgrades, and you'll want to have as many as you can at all times; a single death will take them all away, so it's imperative to make the chance of you dying as small as possible.
The stages aren't actually that long, and you'll be thankful for it, as Tecmo snuck in a very mean trick near the end. After stage 20, you are no longer allowed to continue if you die: should you lose all lives, you're sent straight back to level one. Prepare for a lot of restarts before you're finally good enough to tackle the final seven stages without losing all lives!
Once you finally make it to the end the final boss is expectedly anti-climactic; with an extremely predictable pattern and little life he'll go down very fast. After that you're treated to a really simple ending screen, after which, you guessed it, the game starts back at the beginning with increased difficulty!
In terms of graphics, Rygar is quite pleasing to look at. The levels have a decent amount of variety in objects and the background is different for pretty much every single stage. The music is less good, however: a single song plays during all 27 stages! It's not really bad, but after a while you'll definitely be wishing you could listen to something else.
Rygar is a mixed bag, really. Those looking for a challenge will definitely find their money's worth here - although you can adjust the game's difficulty level, even on the easiest setting, the game will be extremely tough to clear without practice.
On the other hand, of course, this means that unless you're willing to invest a lot of time, the game will likely not appeal to you. Although it starts off pretty easy, the difficulty ramps up extremely fast - you'll soon be swarmed by enemies from all sides with almost no chance of fighting back, frequently leading to situations in which you just can't survive and have to take a hit. Add to this the fact that you can't continue during the final seven stages, and most will find the game too challenging to invest much time into it.