To balance that you'd add more types of levels, maybe different locations to make the game less boring too, with terrain features that block attacks, bosses, new enemy types (tunneling enemies, missiles, aircraft, etc.), challenge rounds (mass assaults by different enemy types, e.g., can you kill 100 infantry launched at you all at once), etc.
The airstrike shop item should be able to allow you to buy more airstrikes per level. The repair bot and attack bot should allow you to buy more of each of them and they should be destroyable by the enemy, so that you should be able to have 4 or 5 of each type of bot for a level, but they suffer attrition from enemy fire. Landmines should be upgradable as well, more of them, then mobile mines, mines with area effect, or mines that re-spawn over time, etc. The invisible upgrades shop item should upgrade to let you see them at different distances and at max should give you an indicator of where on the screen enemies are about to appear. The slow shop item should be upgradeable to wider areas, eventually covering the whole screen. Shield upgrades as well, more max shield hp, ability to block electric damage, etc.
The shop needs to have multiple levels of purchases! Better Guns or more of them, e.g. tri-barrel, cannon, dual cannon, machine cannon, laser, rail gun, etc. The Rear-shield should also have levels, probably based on what it's made out of, steel, hardened steel, composite, adamant, depleted uranium.
I only see three issues with the game, the first is that the first couple levels are too hard, second it needs a speed up button, and third your melee units need to heal over time or there needs to be a spell that heals all your melee units.
I don't know what you guys are complaining about... this is a nice game and a bit different from the typical TD games out there, which is nice. The speed up button everyone's commented on would really make things better, but other than that... it's pretty good. 4/5
For some reason if you get a more advanced achievement first it won't give you the lower level ones.. e.g. save 1k bubbles, then you don't get save 500 bubbles... bad design...
There is a HUGE glitch/flaw in this game regarding inventory. There's no way to throw anything away. Because of this it's possible to get trapped with no way to continue and no way to pick up the items you have to pick up to continue when you are not allowed to sell items due to not being near a shop! Very bad design. This game just got a 1/5 from me.
There is a HUGE glitch/flaw in this game regarding inventory. There's no way to throw anything away. Because of this it's possible to get trapped with no way to continue and no way to pick up the items you have to pick up to continue! Very bad design. This game just got a 1/5 from me.
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those will be fixed in the next update, please stay tune :) Thank you for playing~