I typically play games for medals and the sense of achievement they come with, but in that regard I also look for how medals accentuate game play. Medals can make a game more fun from the added challenge and also that they let you experience the game in a way you otherwise wouldn't and/or explore the game's outer limits.
Some people just throw pointless medals into their games like 'play for 5 hours' or beat the game without getting hit. The first is arbitrary and if you beat everything the game has to offer far under that limit, it becomes a pain to reach it. The second can be done well, but is often implemented for artificial difficulty. The main problem is the high level of penalization for failure. Nobody wants to invest ten minutes or more when if they fail they must repeat those ten minutes perfectly. It also is extremely annoying in games with random variables that can one shot you, making you have to replay the game. In either case the game loses value for those medals.
The point I'm making is your game perfectly accentuates medals with game play. There are the standard complete the game medals, followed by the end-game style challenge medals. The don't-get-hit medal is in a stage of predictable patterns without a high level of penalization for failure. Making it challenging but possible.
The rest of the game on it's own merit is well done; tight classic style graphics, customizable and upgradable ship that never gets so powerful the game becomes a walk, and a variation of enemies following patterns that enable you to with practice beat most levels with little to no damage.
The ship is a bit bulky, but it works fine within the context of this game. You will be unable to avoid the fine particle waves some enemies shoot out, but all bosses can be defeated without getting hit.
But, yeah, this is one of the rare games I enjoyed throughout the entire game and throughout getting all the medals for it. Great work!