The list is far from exhausting. I just randomly selected top down space shooters. So I am sure I missed some good ones, so if you know about some other game I should try, please let me know!
Please do not consider these as true reviews since I did not finish a single game and gave it only short amount of time. I just wanted to see main mechanics, controls and graphics.
I have to say that competition is quite poor. I was afraid that there are many free games and no reason to buy another 'shoot em up' game. I was so wrong. The free games just suck. All of them. The paid ones were quite good and can really be an inspiration for me.
I also found some other 'top shoot em up games on ios' articles:
Free with ads or for $0.99.
Graphics could be better, but it had nice retro feel. Asteroid explosions were terrible though.
You move ship, it shoots. You dodge and shoot asteroid that are coming at you with inceasing speed over time and collect astronauts. Thats IT. No power ups. No more levels. No more enemies. Nadda. It is a shame, I feel like it could have been good game if it had more to offer.
Music, controls, overall feel
lack of content, achievements.
Another rather unfinished game. One background, random ships and that's it. I don't know if there are any power ups, probably not. I did not care to play it for more then few seconds.
This one is just stupid. Enemies do not hurt you, but if they reach bottom of the screen, you lose life, sometimes they drop something, but you can't pick it up, since you can move only from left to right. The music and sounds make you hate the game.
It offers some in-app purchases to make the game easier. I do not really know why would anyone buy that.
graphics - the ships look good, but the whole looks, I do not know how to say it. Cheesy? Childish?
music - I had to listen to it for like 30 seconds and already hate it.
Just standard shooter with weird weapon mechanic. If you destroy enough enemies, boxes with weapons open after few waves. Unopened box acts as a mine. Graphics is good, but boring.
bugs - if you quit game, and start, you start with full health at the stage you quit.
variaty - After 15 stages, the game was more or less the same.
Ignores advantages of that offer side-scroller.
It is playable, but boring, slow and looks like a product from some tutorial.
A decent free game. It has nothing unique about it, but it is well executed compared to other free games.
Speed of bullets. They are slow as hell, your ship is much faster and many enemies can also outspeed them...
Levels are slow paced.
There is also paid version, but it seems like that it only adds adverts, so I consider it free.
You can move only left and right, shooting is automatic, you have limited special attack and alternative attack that consumes ammo you collect.
Controls. Even though it is only left and right,
It is kind of ugly, but graphics works together. What I really hated were walls of text coming at me out of nowhere and I did not really cared to read it.
Walls of text in statistics screen, when I saw it I was immediately uninterested in stats.
There was nothing to surprise me, but I did not care to play long enough to see bosses.
Everything about this game is meh. Primary attack is meh, Special attack is meh. Enemies are meh. It just wont hold your attention for long, you will get bored. Otherwise it is well executed. It feels finished.
Controls - movement on one side, fire on the other, it controls weird and buttons are too small. it would be better if whole half of the screen would be left/right and buttons somewhere for attack.
Free with in-app puchases (additional ships, one for $0.99). Graphics are top notch for free game, better than some paid ones. Other than that it is standard. Paid ships have special abilities which might be interesting though.
Standard shooter, touch control, auto-shoot.
Size and shape of ship makes it hard to avoid projectiles.
No checkpoint, you always start from beginning. If you grind enough points, you can buy some continues.
procedural generation - I love procedural generation, but this one sucks, I would not know it has it if I did not read it in the description.
Everything is too large, so you don't have to aim.
This might be the best free games if you have enough patience to get used to the controls. It's somewhat worse clone of geometry wars, a bit uglier, but you can have great time with it. For me, controls killed it :)
Weird controlled standard shooter.
Long boring cutscenes
Graphics are disappointment compared to cutscenes
slow paced and easy,
controls - I just hate to control these types of game with joystick, it just does not feel right.
Standard with horrible controls - you use tilt to move the ship. Graphics are terrible. I do not know what else to say. Just usual free rubbish. 1 Point is for controls, it may appeal to some masochists.
This isn't real shoot 'em up, but it is similiar to some of the listed games. You move left or right and avoid obstacles that are procedurally generated and try to last as long as possible. Simple, addictive, free, well executed with no major flaws.
PAID (max $2.00)
Well, this is classic. Too classic, therefore i can not give 5.
Shogun: Buller Hell Shooter ($1.99)
Whoa. That's what I thought when I started it.
Awesome art, sound, music, controls and mechanics. Yep. I played just the lite version, but will probably buy it. Only thing that bothers me is number of missions, seems like there are only 4.
You replenish shields by staying close to enemy fire, neat.
You bring up weapon menu by releasing your finger.
You can overload weapons.
This is just well executed stadnard shooter. What stands out are probably the graphics. It is not breath taking, but it is detailed and works well together. You can tell apart enemy, projectile and a bonus.
Enemies drop stars and upgrades you collect. One attack, special weapon that charges over time and bomb
Levels were 'starred' angry birds like, so there is some motivation to replay the level and try to achieve more stars.
Traps like stones falling from above, so you have to move away when you see a shadow.
The length of the levels was just right. Not too short, not too long.
Tapping minigame - occasionaly there is some enemy that drop bonuses if you tap on circles that show up.
I think there could be more variaty to levels, some levels are just waiting for a boss to appear.
Ads. Since it is paid I do not expect to see ads.
This is closest to my game I would like to create. You only move left and right, and attack is automatic, but it feels so right!
Conversasions before mission
Variety of missions
weapon upgrades - minimalistic and smart. You don't get something that kills everything on screen early, nor useless guns.
This is real modern shoot em up. Fast paced with awesome graphics. Every level last just few second and every level has different enemies that are not just visually different, but has some twist to it.
PAID (more than $2.00)
I do not consider these as a competition since they are far above my price range, I played the lite versions just to see if there are some unique features I could borrow :)
I was expecting much more. Lite version is like 30 seconds or so, but I already know I would not buy it. It is classic bullet hell with no additional features.
reduced screen size - there is this useless frame around game screen.
graphics - even though it feels like lot of work were put into it, I just do not like. Screen is constantly filled with coins, explosions or numbers so you don't see anything and the resolution is so low. But it has this arcade feel, so somebody might like that
This one would probably needed more time than I gave it. It is like Bug Princess 2 done properly. Well it is probably sequel or something, it looks very similiar.
It is much more readable than Bug Princess 2 - no more shit covering the screen. Game space is full scree, no more stupid frame around. Many fire options.
Many instructions to read through if you want to understand what is happening.
Lite version got me curious, but I am yet to play the full version. But it should be good, damn good :)