I believe most games are written for EGA cards with 256k of memory installed.
I'm pretty sure Keen is.
The original IBM EGA card shipped with only 64k, and an optional memory expansion could be installed.
So, make sure that you have 256k installed on your card, else a lot of games will probably not work correctly.

IIRC, tile-based scrolling needs utilizable memory beyond 64kb.

I could be wrong, but I always thought Keen was written with VGA cards in mind and merely used EGA because of that dual-page mode..
By 1990, the EGA card was already 6 years old and got supersed by VGA just 3 years ago.

Anyway, I believe that memory issues *could* be among of the issues. 😐
A VGA card has the full amount of EGA memory. 64KiB is by far too little. This can't even handle 640x350 properly.
That amount of RAM i's nice for beefed-up CGA games with 16 colours, though. Especially if no real EGA monitor is used, anyway.

"The original IBM EGA card had 64 KB of onboard RAM and required a daughter-board to add an additional 64 KB (cards with 64 KB are limited to
four colors when 640×350 mode is used). All third-party cards came with 128 KB already installed and some even 256 KB, allowing multiple
graphics pages, multiple text-mode character sets, and large scrolling displays."
https://en.wikipedia.org/wiki/Enhanced_Graphics_Adapter

Also, timing is different, as well.
VGA runs EGA modes in 70Hz, whereas real EGA runs at 60Hz.

As well as the small amount of memory original IBM EGA cards were pretty crappy compared to the clones. Most vintage computer forums I visiyt come to that conclusion. VGA came out in !987 with the IBM PS/2 lineup.

Yes, the clones were pretty interesting I think. EGA in itself - especially as a mode - was fine.
Just the original technology used for it wasn't quite ready, maybe. By comparison, I wonder how the IBM PGA card performed in terms of reliability.
Speaking of the enhanced EGA clones, they quickly adopted the standard VGA resolution of 640x480 pels in 16 colors.
This was true for both the VGA mode number, as well as the default 16 colour palette, I think, which was based on EGA.
Some card even went beyond this and offered a serious resolution of 800x600 (Super EGA ?) if paired with multi-sync monitors.