So I played the game through. Here's what you need to know:
1. at the end of each level you can click the green "Check Mark" repeatedly for lots of gold. 2. the alien weapons are the best. 3. I thought the maxed out purple long-range weapons are the best you can buy. 4 the weapons you can build are never as strong as the ones you can buy. 5. regarding the lack of re-playablity of the levels... don't worry the game is too long, and everything will be maxed out by the middle of the game. 6. and because it all is maxed out by mid game, there is not point in playing. the end screen is boring, the game play never becomes challenging. It is in fact the exact same all the way through. there are never any Big Bosses. 7.One Star. 4 to 6 hours to play. Also, I am almost certain I got the "You Win" screen on the 2nd to last planet.
I am not sure if it is a Bug or an actual feature of the game, but at the end of each level, when you get the green check in a box, each time you click this you get the reward. IF you can manage to click it a hundred times in the couple of seconds it is there, you will get gazillions of gold.
This is an endurance badge.... I found that getting groupies is a cash multiplier (up to x3?), but you loose them (they die) when you crash. if you stick to a simple reverse flip and a jump, you can make a lot of coin from early on.... by my 80th jump I was consistently making >1000 coin. However, by my 160th jump I was still in a moderately upgraded 'normal' cart. Slooooow progress!
Just in case you missed it, an important/ kind of unique part of this game is something called "Scraping." This is when the edges of your ship 'scrape' across the bullets. Apparently only core/center of your ship actually takes damage, and -if you have the right accessories (Over Drive & Absorption Panels) - you can shoot super fast and hard, and/or charge your energy very quickly.
The secret to this game is to set up one "Super Death Alley", and then to set up your maze so that once the mobs go through your focused damage area, you open the beginning of the alley and make the mobs turn around and go back through... Repeat until all mobs are dead. This allows you to focus your coin on fewer, but more powerful and more concentrated towers. Even the hardest parts become easy.
The guaranteed winning combination is 2 ninja and 2 cats: I was able to get >30,000 points on level 17. .............However, it is worthy of consideration that the witches' special is the same as the cats, but the witches shoot faster and bring "+20 SPECIAL" -- making the most important thing - your special attack- refresh MUCH faster.
I think the game has a lot of great potential -- I almost really enjoyed playing it -- but all in all it was completely anti-climatic.
In the end the most difficult thing was moving my mouse around fast enough to grab the dropped turtle egg/coins... This game seriously needs a 'coin magnet' upgrade. Another option would be an upgrade that lets your penguins collect coins as they come in contact....
Each of the areas of levels should end with an EPIC BOSS.
Level 30 (the last Desert Level) = around $15,000 per replay, which is approximately twice of any other level.