SmoothKeen 1

[Multimania]

Commander Keen may have pioneered smooth scrolling on the PC, but what if it were even smoother…?

Introducing SmoothKeen 1, a quick hack to run Keen 1 at higher framerates:
http://davidgow.net/files/SmoothK1.zip

What is it?
A modified version of Commander Keen 1 (Marooned on Mars) with the framerate jacked right up to maximum! Play Keen at 70 FPS, not 24! Experience a large number of strange bugs. Enjoy some smooth VGA palette fades. Have your muscle memory betray you!

How was is made?
It's based off K1n9_Duk3's keensource123 decompilation, with the 'MINTICS' variable in KEENDEF.H modified. A few other minor changes were then made, including:

• All of the recommended changes to build it with Borland C++ 3
• A number of small physics changes to make Keen's jump and pogo height more consistent with the original game.
• Better framerate-independence for the world map movement.
• A fix for the behaviour of doors, in order to make them less flickery.
• VGA palette fading.

That being said, the new physics is not identical to the old physics, and there are several things which may move further, or faster, or slower, or differently.

Also unchanged is the VBlank handling. Maybe CRT Terminator support will come in the next version.

Edit (2026-03-28): Updated this to add Keen 2 & 3 .EXEs. They're largely untested, but feel free to give them a try!

Special Thanks
This couldn't have been done without K1n9_Duk3's decompilation work, I just did some quick hacks to it.

Also thanks to the following patches, which paved the way:

• adurdin's "Keen won't 'bounce' off doors" patch
• lemm's original "Change framerate" patch
• Dr Kylstein's palette patch.

And also some inspiration from the Foray in the Forest palette code, again by K1n9_Duk3, and Chocolate Keen, by NY00123 and lemm. Thanks all!

Extra Special Thanks must also go to the whole original crew at id and Apogee who brought us the game. Thanks all!


Happy Keen Day!

[Roobar]

Oooh! Neat! This makes the game really smooth and more enjoy-able! Feels much easier to control as well.

[SergeantSolar]

This is cool! Always love an excuse to do a Keen1 run.

Thank you for this.

[K1n9_Duk3]

This is pretty neat, but I have one minor complaint about the presentation. Section 2 a) of the GPL version 2.0 states:

You must cause the modified files to carry prominent notices stating that you changed the files and the date of any change.

That didn't happen here. Just to be clear, I am not saying that every single change has to be marked with comments (although that could also be helpful, see below), but you should at least mention that the file has been modified in the comments at the top of the file.

Since this appears to be based on the initial release of my reconstructed source, which is no longer available via the original link, it's harder to compare this code to the current version of my code to find out what you had to modify to achieve the smoother motion. Additional comments that mark the lines you have changed would make it easier for modders to add these modification ito their projects.

[dark]

This is very enjoyable to play at the higher framerate. Thanks for sharing!

[Benvolio]

This is good fun! The differences are very noticeable upon loading the game but actually become more subtle when you get involved in playing through the levels. The physics is interesting - definitely different, throwing my off slightly especially when it comes to pogo accuracy. Though of course I am likely horribly out of practice too which is also a factor. Nonetheless the physics differences are subtle and I agree with Roobar that in some respects it's smoother to control. In other words, if this was the Vorticons engine we were used to it would be objectively easier than the original, but familiarity makes the original still easier to control.

[K1n9_Duk3]

Sorry about my last message. What I meant to write was:

I am not saying that every single change has to be marked with comments.

I was in a bit of a hurry and tried to rephrase that sentence right before I posted the message. Some parts obviously got lost in the process. Starting the sentence with "Just to be clear" and then completely messing it up and writing the opposite of what I wanted to say is pretty ironic ... and embarrassing. Again, sorry about that.

[Multimania]

This is pretty neat, but I have one minor complaint about the presentation. Section 2 a) of the GPL version 2.0 states:

You must cause the modified files to carry prominent notices stating that you changed the files and the date of any change.

That didn't happen here. Just to be clear, I am not saying that every single change has to be marked with comments (although that could also be helpful, see below), but you should at least mention that the file has been modified in the comments at the top of the file.

Since this appears to be based on the initial release of my reconstructed source, which is no longer available via the original link, it's harder to compare this code to the current version of my code to find out what you had to modify to achieve the smoother motion. Additional comments that mark the lines you have changed would make it easier for modders to add these modification ito their projects.

Sorry about that — I usually just let git handle changelogs, but I didn't use it here.

So, I've updated the version with the more prominent copyright notices. I've also rebased it on top of the latest keensource123 and included a complete list of changes as smoothkeen-changes.txt in the source code archive.

And finally, I've included binaries for Keens 2 & 3 — you can copy those into an existing Keen 2 or 3 installation to give it a go. Completely untested, though.

Code: Select all

Changelog:
----------

2026-03-28:
 - Rebase on top of latest keensource123
 - Include Keen 2 & 3 binaries

[Roobar]

Oooh! I like untested things. I'll give Keen 3 a try. Hopefully will find something amusing

Edit: After some playing, there aren't that many amusing issues. The biggest issue are the moving platforms. Not only they do constant sounds, but you cannot stand on the horizontal ones without pushing the keys to go along with them. This makes certain places not impossible, but extremely difficult.

Other issues include some enemies moving seemingly faster (like the bouncing balls and ninja dogs). The only somewhat beneficial thing that comes out of the increased speed is that Nessi now moves a lot faster, thus it recues the waiting and riding time.

Overall, unlike Keen 1, smoothing makes Keen 3 actually harder.