I dunno, it's really tedious, and there's a lot of times in which I really wished the sight I had available was just a little bit further out and up because either there was about 12 boosters I passed that was out of range by the time they showed up on screen, or I'm aimed into a wall of UFO's. And then there was about 30 times in which I was upset because my pilot had suddenly developed down syndrome and suddenly started to take his remaining mangled wreck of steel and shove it into one of the booster nodes instead of between them. Even with the max everything it handles like a drunken slug. It wasn't quite fun... it reminded me of 'Upgrade Complete'. You had to buy everything first before it was even remotely playable. Otherwise it's just watching a rocket plow into everything and blow up because it got nicked by an airplane propeller, while you pass all the powerups and boosts and anything that would make the game fun.
I wish there were two things: first, sound effects would've been great, IE shots, impact, etc. Two, being able to choose which upgrade you want to use after buying the next level. I actually think level 3 graphics and level 2 music are the best. Also, maybe upgradable menu screen music at that.
The fifth challenge is just stupidly ridiculous. I've spent just as much time trying to clear that as I have all the rest of the game, including the hard campaign and the other 4 challenges, and I haven't cleared #5 yet. Yay, hard = fun again! Not.
 "Burrito Bison: Launcha Libre"){kind=icon}
 "Prizma Puzzle Challenges"){kind=icon}
 "K.O.L.M."){kind=icon}
 "Bloody Sunset"){kind=icon}
 "IntoSpace!"){kind=icon}
 "Anti-Idle: The Game"){kind=icon}
 "UPGRADE COMPLETE!"){kind=icon}
 "Homerun In Berzerk Land: Berzerk Ball"){kind=icon}
 "Continuity"){kind=icon}
 "Wake the Royalty"){kind=icon}
 "Super Energy Apocalypse : RECYCLED!"){kind=icon}
 "MoneySeize"){kind=icon}
 "GemCraft"){kind=icon}