The major flaw I see with the game is the upgrade scaling. The first cannon fully upgraded is better than the second just purchased- and by the time you spend enough money to make the second cannon equal to the first, you could already buy the third.
Also bat-gang- should not stop upward momentum.
Not sure if this has happened to other people but at the last boss I had a full rune set, all my AI allies were dead and then my player hero died. I was supposed to resurrect but the game froze and all my data was lost when I refreshed. Probably a glitch with mission failed and resurrection. I've noticed that I also don't always resurrect when I should.
Continued from my other comment!
Major lack of variety. Slow mechanism plays into this. It seems like the mages and archers are the same, and the only difference with the cannon is a little bit of damage and splash. Otherwise they all just feel like the same ranged tower. Also splash becomes ineffective when a) the only way I can make units group together is through the wind spell and b) the area of effect is tiny and can't be increased through upgrades. Another thing I noticed is almost all of the upgrades are the same across each path just reordered. Perhaps that would solve the way people are asking for tower upgrade splits- rather than putting them in game if you can't implement that, put it on the upgrade tree.
I'm not going to reiterate the speed-up button, but speed-up button.
I gave the game a 3 because I like the play and feel, just there's some elements missing. Maybe I'm crazy also.
A major issue with the difficulty is the lack of the slow mechanic found in almost all tower defenses. Something like the Trojan Horse is unstoppable by units so it's a little problematic that it can roll on by with four level four towers pounding on it. The Golems and Ents I can live with because they stop slightly for ground units although not really. Perhaps as an easy fix make the mages have an upgrade to slow.
The tower stacking mechanism. This is interesting because it's pretty creative. However, the way range moves it essentially kills a "choke point." When a towers upgraded, the range shifts, moving either out of where I want it, or into where I want it. Either the bottom tower or the top tower has what I want in range for a long time, but not both. This quickly becomes cost inefficient.
There are three main problems I see with the game.
1. A minor glitch. When I was in game, I was trying to evolve only plants, but kept noticing animals. When I loaded previous saves, I noticed that whatever I had done after the save still affected my save file i.e. I could buy every upgrade by reloading over and over.
2. It seems that all the bouncers/objects appear in columns. When falling very fast I noticed there were spots you could go without hitting anything.
3. Difficulty is rather easy. Perhaps add in a mode after completing original, with moving obstructions.
Otherwise, great game. The evolution concept was a great addition to the launching genre.
The medal awardance should be based on number of mistakes and and wrong key presses, not score because people mess up at critical points (x10 multipliers) or really high ones, then the score was lowered. I got a bronze for missing 9 keys on a easy song.