This was a little too frustrating to make any progress for me. Would have been better to gradually introduce enemy types, instead of just a barrage on the first level. Shooting in only in the direction of movement is an interesting mechanic, but the sheer number of enemies and bullets makes it feel impossible to actually get ahead when you have to fly back into the bullets to even get a hit on an enemy!
There was also a weird bug where I tried playing the Til the end mode, and then any time I play either mode after that all the time is sped up to a ridiculous degree haha. With some tweaks to the enemy count this has potential though, so nice work!