Underwater+ I played the first one and after playing this one I felt like writing a review about the problems of this game:
Graphics/Animation : 1/5
The water is just a one-coloured surface, the swimming animation consists of only a few frames, the jellyfishes are just a moving, unanimated sprite. The attack animation is also not good.
Audio: 3/5
The song is well chosen but you could add an option to choose between more songs. It would be also good to add sounds for : getting a coin, attacking a jellyfish, getting a bubble, etc.
Content/Gameplay: 0/5
That may seem harsh but I will explain why you get no points in this category. While there are some much needed improvements over the last game, it is still too difficult to get coins and an overall unenjoyable experience.
I upgraded everything to a point where the upgrades cost 40$ and there are still multiple rounds in a row where I see nothing, no coins, no enemies, nada. Since it becomes more and more costy to get an upgrade, the game becomes more tedious the more upgrades you have. The one-time upgrades help a bit to counter this problem but it is not enough.
In other upgrade games you feel more powerful as you keep on playing - in this one you will feel more and more unlucky.
The spawn rate for everything apart from the jellyfishes is way too low. Why bother to upgrade bubbles when I see one in 10 rounds? Upgrading bubbles should make them more efficient and increase their spawn rate. I also found the attack to be absolutely useless. The jellyfishes get barely knocked back and most times you will just crash into them when you attack. The hitbox of those monsters is also insane, they are cleary far away and the still hit me, tone it down a bit.
I also recommend that you add some upgrades that make the game easier and more enjoyable:
- Hearts upgrade: Each point gives you one more heart. That will prevent rounds where you suddenly crash into a jellyfish and gain nothing. Once you get hit, you will be immortal for 2 seconds, so that you have time to move away from the jellyfish.
- More treasures! upgrade: that will improve the chance to spawn gems that give more than just one dollar. That will help to keep high priced upgrades obtainable without playing several years.
- Improved weapon: instead of knocking the jellyfishes back, they will now get damaged and slowed down. The jellyfishes will have 5 hitpoints, once you have upgraded weapon 5 times, only the amount of shots gets improved.
I am so lucky! Upgrade: The most costy upgrade, starting with 10, and increasing by the same amount, can be upgraded 5 times to increase the spawn rate of bubbles, coins and gems a bit.
Apart from that, once you got rid of those flaws it would be nice to see more content:
- first would be a high score for how long you survived, one for how many coins you earned in a round and another one for how many challenges you cleared
- a challenge mode: you get quests that you have to solve, with incrasing difficulty, for example "obtain 3 coins in one round", one of the later ones being "defeat 3 jellyfishes within one minute", etc. The higher the difficulty of the challenge, the higher the reward will be, giving the player an optional way to gain enough money for the upgrades
- unlocking skins for the player, and skins that add more monsters than just jellyfishes
Overall: 1/5
As it stands now, the only good thing is the relaxing song - which stands in a strong contrast to a gameplay that is in most aspects simply annoying - you don't look forward to upgrades and more often than not unfair jellyfishes spawn directly before you without a chance to react. The game in its current state simply is no fun to play and the one point is only given to put it in perspective to the first one. I hope that you don't get discouraged by my honest rating - I also recommend that you play some of the upgrade games here on Newgrounds to get a better feeling what that kind of games need to be fun - steadily more upgrades that make you feel more and more powerful.
DownFall 
