In an all-time list of great C64 games (or 8-bit games in general), Uridium should be near, if not right at the top of the list. At the absolute peak of his creative powers, Andrew Braybrook created the kind of effortlessly innovative and visually slick horizontal shooter that even die-hard Spectrum fans liked.
Unlike every other shooter in awe of the on-rails coin-op style, Braybrook seemed to realise he could come up with something much better than anything we were playing in the arcades. Uridium set players free, allowing them to fly their Manta Space Class Fighter freely over 'Dreadnoughts' which you had to systematically destroy by shooting the majority of its surface defences.
Doing so wasn't especially straightforward, because wave upon wave of determined enemy fighters would appear from the left or right side of the screen, forcing you to dodge and weave around the metallic environment, desperately trying to avoid impassable obstacles that littered each dreadnought. Worse still, homing mines would appear from certain sections of the dreadnought if you lingered too long, again, forcing you to skilfully outrun it.
Demanding careful piloting skills, you'd also often find yourself forced to turn the ship on its side in order to slip through narrow gaps, and line yourself up correctly in order to land on the 'master runway' towards the rear of the Dreadnought. After each of the 15 levels, you'd engage in a typically enthralling Braybrook mini-game, where you'd have to press the fire button at the right time in order to pull fuel rods from metal converters. Every time you succeeded, the process would speed up to the point where it was more luck than judgement whether you scooped up extra points.
After that, the Dreadnought would vaporise spectacularly, allowing you a chance to shoot any remaining defences on your reverse journey.
With absolutely stunning metallic background graphics, slick animation, a wonderful theme tune and a finely honed learning curve, it's hard to think of a better shooter on the C64 - apart from the remixed Uridium +, perhaps.