Hyper-5 (EP)

Like a few others, I completed Hyper-5 without this achievement popping, despite having bought far more than nine upgrades from the armoury. I have seen people mention that this achievement is glitched and this appeared to be the case for me too.

After finishing level five and getting all the other achievements, I deleted my save using the 'from everywhere' option on the Xbox and then restarted the game from the beginning. You should be able to buy a few upgrades with the 2500 points you have at the start of the game. I bought the basic gun upgrades and the rocket upgrades that were available. Playing through the game again, and buying the cheapest upgrades available at every chance, I was able to unlock the achievement by the time I reached the start of level three.

I'm only guessing, but I think the reason this achievement might not pop for some people might be related to using the downgrade option on weapons, where you can recover upgrade points.

Hope this helps some of you who are frustrated that this achievement hasn't unlocked.