This is the biggest hurdle. Feature phones have processors clocked in megahertz, not gigahertz.
This is the trickiest part. Rovio never officially released a public VXP version of Angry Birds. The existing files are community-converted or extracted from phone firmware. Here is where and how to find a reliable file without downloading malware. vxp angry birds 320x480 work
This is the HVGA (Half-size VGA) resolution. It was common on early budget Android phones (e.g., HTC Tattoo, Samsung Galaxy Ace) but also on many feature phones with touchscreens (e.g., Nokia 5230 series, some LG Cookie models). However, standard Angry Birds for J2ME was often designed for 240x320 (QVGA). A 320x480 version requires additional graphics assets and altered touch coordinates. If you run a 240x320 version on a 320x480 screen, the game will either appear in a small window or crash due to scaling errors. This is the biggest hurdle
Your 320x480 feature phone likely has only 64–128 MB of RAM. Angry Birds (even the lite version) is heavy. Here is how to make it run without stuttering: Rovio never officially released a public VXP version