There are a number of side missions that pop up as you progress, but these are often objectives that you would hardly be able to progress through the game without completing - kill a certain number of enemy grunts, rip a certain number of train carriages etc. But since enemy grunts are plentiful - and have to be killed or they will kill you - and train carriages have the annoying habit of being stuck in places where they completely block your way forward if you do not rip them, it would be difficult to make any meaningful progress through the game without completing these challenges.
Nathan's bionic arm can be used for more then just swinging around the game environment. It can also be used to hack Relays - communications computers that are scattered around the game world. Relays intercept all communications in their area - and by hacking them, elements of the narrative are revealed to Nathan. Hacking them also enables Nathan's controllers to triangulate his position and drop him supply pods with additional weapons. Each Relay is protected by a number of enemy combatants, and Nathan has to dispatch these before he can hack the Relay.
The final (and after getting around, most important) use of Nathan's arm is in combat. He can use it to attach to an enemy, then perform a devastating kick - but beware, certain opponents can send an electrical shock down your extended arm that injures you. The arm can also be used to rip certain parts of the scenery to clear them out of the way, or to drop them onto enemies below. As you progress through the game, although you'll get a selection of better weapons, you'll also encounter tougher opponents that require some strategic thinking, and the use of Nathan's skills and abilities in order to defeat them.
There's a certain trial and error aspect to many of the situations you'll find yourself in which is in part down to the fast moving aspect of the swinging mechanism. You can often find yourself in locations or situations that you have not had time to evaluate. This results in your unceremonious demise and you then re-spawn at the last waypoint, which is never too far back.
In the end, as at the beginning,
Bionic Commando is a perfectly decent game, and one which, although it did not grab me in the first few minutes of playing it (they were slow, uncompelling minutes) certainly managed to entertain me after the first half hour or so. The learning curve is not exactly steep, but getting skilled with the swinging method of travel is tricky, and it can be frustrating until you have it mastered (and even afterwards).
Until you learn to detach and re-attach your grapple you can often find yourself stuck. Certain areas of the playfield are irradiated, and Nathan can only survive in them for an incredibly short period of time, often too short for you to get back out again. Some of the pick-ups are placed extremely close to the edge of radioactive areas, in very tricky positions, and getting them can lead to you dying.
Conclusion
SPOnG Score: 75%
Bionic Commando did not grab me in the first half an hour and, typically, I consider that to be a bad sign. But, with continued play, it revealed its subtle charms. Unfortunately, these were mixed with enough frustrations to make the game confounding - one minute it was immersive and engaging, the next it made me want to throw the controller down and go do something, anything else. But in the end, I never did, and even now I'm waiting to get back to it... which has to be a good thing.