Edited on June 10th, 2016

As of the current version, the current state of the game has improved compared to the dark souls level of difficulty from the first version. Though, there are still a couple of issues to point out, but will be addressed in the next version.

1. You can't attack and immediately inflate/deflate the size, since the game will only do that if you're not in the shooting animation. For a fast-paced game, this is especially bad and creates input lag/delay, forcing the player to wait a little before changing size. 
   1. I'm aware that this may be fixed in the next version.
2. The collisions are janky and often get you stuck. This is especially when changing size via inflation, and it's more apparent in the second map in a tight narrow area.
   1. May be fixed in the next version but can lead to sequence breaking or skipping sections of the map.
3. The enemies are kind of unfair, but less than the previous version due to the new health update. The turrets have a small hurtbox, coupled with the player bullet's small hitbox (And other factors, such as ridiculously high fall speed) makes it rather difficult to take the enemy down in 3 shots. You cannot aim your shots; you'll just have to either inflate to rise up or just wait until the turrets is within jumping distance.
   1. The grounded enemy, once it shoots, hardly has any delay in-between shots, making it much more difficult to take it down, even if it has 1 health.
4. The level designs have bad telegraph, and it doesn't tell the player that you should use the inflate mechanic at certain areas.
   1. The first level is apparent, where you fell down into a pit of spikes not knowing that you'll have to inflate yourself at the right timing before hitting the spikes below (or just hug the walls to the right to avoid that). Though, with the new health update, it doesn't instant-kill you anymore but still keep in mind in future level designs.
   2. The second level is also apparent as well, as it doesn't show you the bed of spikes below until you fall down during the turret section. Following that, but the enemies that waits for you to deflate back to normal makes it near impossible to just jump down and attack the enemy before it attacks you first.

Side Note: When you actually get used to the mechanics and knowing the patterns of the stage, it does get easy. I manage to get over 8000 score without taking a single damage/life.

Overall: While it does have some rough edges, the gameplay is promising and I'm looking forward to the next version. Though, a little nitpick is the inflation to be slowed down a bit, but that's just me.