Operation Echo Demo Released! [SideScrollShooter]

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Operation Echo Demo Released! [SideScrollShooter]

Postby GreenLegacy » Sun Apr 01, 2018 12:58 am

Download demo
Youtube Channel
Email: nateddmp@gmail.com


Echo is my first commercial game. It is created by GZDoom engine and influenced by several side-scroll-games such as Metal Slug, Megaman, etc.
I decided to create a game that better than the Black Warrior.Unfortunately, the development of the Black Warrior has been stopped, but I hope you enjoy this game instead.

Thanks again to GZDoom developers for making this game possible to develop. =D

Spoiler: Demo gameplay screenshot"



M16 is the protagonist of this game.
He was famous butler robot.But after Mutant Armageddon started, he got the order of Dr.Miller who created M16.His mission was saving the people's life from the mutant. After adding combat capabilities to M16.He armed with plasma weapon and combat gear that never has before.Now all he needs to do is eliminate all enemies to bring peace back to the earth...


Story GreenLegacy

Pixelart GreenLegacy Mzom

Music & Sound GreenLegacy

Level Design GreenLegacy AtroNx

Programming GreenLegacy


Development has started in Feb 2017. I am planning to release a full game hopefully before the end of 2018.

[Program used]


[Last words]

Criticisms are welcome!
I would appreciate it if you could send me a bug report or criticism directly by email or leave a comment.
Last edited by GreenLegacy on Sat Apr 07, 2018 6:57 am, edited 3 times in total.
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Re: Operation Echo Demo Released! [SideScrollShooter]

Postby PlayerLin » Sun Apr 01, 2018 7:15 am

Releasing serious project on April 1 maybe not a good idea I guess. :P

The pictures of difficulty selection screen are nod to title screen of DooM (Hard) and Duke Nukem 3D (Normal), very cool! :D

Due to I'm suck at side-scroll shooter, I can't give any of suggest or something, and I give up on the third part of mission 1(where the player control the M16's sidekick, just totally can't get used the hooking and keep fall down, really suck at such games, even I like games like Contra...:(), but still, I think it's good(for me). :P

I found a little inconsistent about the door in the end of the each part that player should be destroy to process to next part of level, in the first one, it give 1 point of score when player attacking that door, but on the second part, attacking the door never give any of score point until it destroyed. It's not big deal just inconsistent. :)
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Re: Operation Echo Demo Released! [SideScrollShooter]

Postby _mental_ » Sun Apr 01, 2018 7:34 am

You shouldn't distribute zd_extra.pk3 because it contains potentially copyright infringing materials.
Also, gzdoom.sf2 is not needed if no MIDI music is used in your game.
Most likely brightmaps.pk3 and lights.pk3 can be removed from the package too.

BTW there is no need to edit gzdoom.pk3 to be able to load your .pk3 as IWAD.
Add iwadinfo.txt file to .pk3 with the same content you inserted into iwadinfo.txt from gzdoom.pk3.
Then change extension from .pk3 to .ipk3 (with 'i' letter at the beginning).
Recent versions of GZDoom will recognize opecho.ipk3 and load it like a known IWAD.
This way the game can be used with the latest GZDoom and on platforms other than Windows.
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Re: Operation Echo Demo Released! [SideScrollShooter]

Postby Untitled » Sun Apr 01, 2018 9:47 am

I love it. The demo is REALLY good, and I have no idea how this was done in an engine that's clearly not designed for it.

However, if I'm going to make some valid criticisms, it's that:
1. The tutorial, if I recall correctly, never goes over how the energy system works; what with the shield and weapons both using it. It's not that hard to figure out, but it's kind of "maybe you should know first".
2. The cooldown timer on when you can re-use Emily seems completely non-functional - it seems to just zip down to finished instantly.
3. It might just be me, but I didn't find it intuitively obvious you were supposed to shoot the door - I was wondering "what am I supposed to do, and why are there infinitely respawning enemies?" until I accidentally shot the door a bunch.
4. The auto-checkpoints are really nice, but bare in mind you have to be careful with them - if you're at, say, 5 health, and then the game autosaves, the next section can be way harder than intended. This wasn't actually a huge issue in game, but there's a few times I had to figure out how to do a section on 20 health.
5. Maybe it's just me, but the hook shot is really hard to use.
6. The boss seemingly forgets that players can aim upwards; you can slightly cheese it by just standing underneath his mouth during phases you can damage him, then only his summoned enemies can hurt you. The ability of the boss to summon said minions is about 90% of the difficulty of the fight; if you get good summon RNG he's a completely joke. If you get bad summon RNG...
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Re: Operation Echo Demo Released! [SideScrollShooter]

Postby GreenLegacy » Sun Apr 01, 2018 1:24 pm


_mental_ <<< Wow that's really helpful! I removed those entries and changed pk3 to ipk3.It worked well! All I need to do is updating demo.Thank you :D
PlayerLin, Untitled <<< Thank you for valuable feedback! I will consider it carefully and apply it!
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Re: Operation Echo Demo Released! [SideScrollShooter]

Postby insightguy » Mon Apr 02, 2018 12:24 am

as I posted on discord:

"just finished through the first level. the controls are OK for the most part, except for the pink haired girl's controls (that grapling hook REALLY needs more work) and the boss was pretty good for a first boss. Graphics and level design may need more polish but I can see a product here".

Also, why can't m16 fire diagonally?
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Re: Operation Echo Demo Released! [SideScrollShooter]

Postby Kyotra » Tue Apr 03, 2018 12:31 am

Ah man, you killed off that Doom mod you were working on?
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Re: Operation Echo Demo Released! [SideScrollShooter]

Postby ramon.dexter » Tue Apr 03, 2018 6:48 am

Looks nice, but what about some actual gameplay video, or screenshots? I wont download the whole game just to see how it looks. Also, the video has 3 minutes. Half of the video is only text. Is it really neccessary? Wouldn't be better just 1:30 video? Or is important the music, that plays while the logo is displayed (seriously, you dont have to even notice this. Its just my OCD when i see a part of video that is completely static, I just dont understand why it's a video, when the video is displaying only text...).
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Re: Operation Echo Demo Released! [SideScrollShooter]

Postby GreenLegacy » Tue Apr 03, 2018 7:20 am

insightguy<<I agree with your opinion! It's hard to control I will improve Emily's grapple hook in future version :D
Kyota<< No, It's not a dead project! I will develop Blackwarrior again after finish this project. don't worry!
ramon.dexter<< Sorry for the video that I made lack of information.Instead, you can watch the gameplay screenshot in here or Gamejolt. I'll do my best next time XD.

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Re: Operation Echo Demo Released! [SideScrollShooter]

Postby GreenLegacy » Sun Apr 08, 2018 9:18 am


Thank you, followers and people who enjoy this game!
I was so happy to see that people love Echo since I upload the demo. :D

For seven days, I've gathered your opinions to make a better game in the future. these opinions below are had mentioned multiple times from users

Gamepad support problem

Sorry for someone experienced poor gamepad support. I'm considering this to be removed or maintained. I'm trying to stabilize gamepad support as I possible. It will take time because the GZDoom engine is optimized for FPS, not for a side scroll shooter. If I fail to handle, gamepad support will be removed :( but don't worry, I will do my best! :D

Unrecognizable graphics

Some people notified me object's sprites(platform or projectile) are needs more work. They said It's hard to recognize the object in the background. (especially outdoor segment.) I will do this better next time.

Level design

Most of the people felt hard to destroy the door or didn't recognize that door can be destroyed. this means I designed the level badly. And checkpoint also the same problem.

Grapple hook's control

Most of the people felt grapple hook was hard to control.

I agree with this opinion too. Grapple hook needs to be more flexible to control. I'm gonna change the mechanism of the hook shot next time.

I'll keep in mind this while I'm developing.


Thank you for your support and I will work hard to make a better game and finish this project successfully! :D

*If you find more just tell me!

Gmail: nateddmp@gmail.com
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Re: Operation Echo Demo Released! [SideScrollShooter]

Postby heron » Tue Apr 10, 2018 10:10 pm

"press anykey"

... where's the 'any' key?!
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Re: Operation Echo Demo Released! [SideScrollShooter]

Postby chronoteeth » Wed Apr 11, 2018 11:49 am

this looks bloody awesome! bout the only thing i didnt enjoy was the pink hair'd girl and the blue hair'd guys design, but legit its like holy moly super solid! great job so far!
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Re: Operation Echo Demo Released! [SideScrollShooter]

Postby GreenLegacy » Sun Apr 22, 2018 4:50 am

heron << Ack, Sorry for my bad English.XD
chronoteeth << I'm glad to hear that you enjoyed! the full game will be better than this.
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Re: Operation Echo Demo Released! [SideScrollShooter]

Postby GreenLegacy » Sun Apr 22, 2018 11:37 am

The new progress of stage1


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Re: Operation Echo Demo Released! [SideScrollShooter]

Postby Captain J » Sun Apr 22, 2018 1:54 pm

Good to see you again in zdoom forum, buddy! You definitely improved your modding skill to maximum and i can't wait for the update, or full release even! Looks very promising. I haven't seen side-scroller games with doom engine very often.

Glad i'm seeing this right here, right now! :D
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