Good potential, but, well, at this state it kinda sucks... And get the lag fixed.
Jump&Run and Bullet hell isn't a good mix, but that's just my personal opineon. Whatever.
I enjoyed the art style. Really, good stuff right there. The intro sequencies to the stages were nicely done and a bit funny. The stages themself were visually pleasing. Sound and music were all right.
I'd give you a 4.5 (-0.5 for lag), but you'll have to settle down for 2, because...
The difficulty. OH GOD THE DIFFICULTY. What.
How is it even possible to screw up the difficulty like that?
I mean... the further you progress, the easier the game gets! WHY.
Come on, I'm running into walls of bullets on stage one without any chance to dodge anything of it and in the second stage I'm dodging drills and homing... psyhodelic... blinking... color droplets... things... (they looked very nice, btw.) Anyway, the key word here is DODGING.
And stage 3 was a total joke compared to stage 2, nevermind the insane bullet barrage of stage 1.
Oh, also, the fact that your bosses and mini bosses are actually easier to defeat than to beat the stage itself should tell you that there is something very, utterly wrong with your game.
No srsly, the bosses were actually a RELIEF from the stge itself (especially on stage one, later they turned into a minor annoyance). There is no challenge in them. At all. I mean, come on, they weren't even trying to actually hit me most of the time. The two worm things minibosses (yep, that's two times the same miniboss, no change in behaviour or anything at all. Running out of ideas, are we?) were just a meaningless waste of time. Oh, and stage four? Oh god, stage four.
I don't know what chances the are for an enemy to drop something, but stage 4 basically just kept throwing health pickups at me, it's not even funny. No, really, like every 2nd or third enemy killed dropped a health pickup. I couldn't die there even if I tried to.
Man, forget about lag or glitches, get that difficulty curve fixed.